Marcus Welby hires brash young Doctor Kiley to assist in his bustling general practice. Among Welby's most pressing cases is a young man suffering from aphasia whose wife is seeking to have him committed to an institution.

Miss Ruth Adams is a wonderful teacher, very engaged with and loved by her children. So when she slaps one of them in a fit of rage, her principal sends her to see Dr. Welby for a psychiatric reference. But her problem isn't psychiatric - it is a gliosarcoma, inoperable - a death sentence for a young teacher just beginning her life and career. Dr. Kiley must break the news to her, and then finds himself increasing drawn into the woman's final days.

Welby fights bureaucratic pressure from a young couple and an unfeeling psychologist as he tries to help the couple's 7-year-old autistic, severely withdrawn son learn how to communicate.

Claire visits Dr. Welby certain she has begun to enter menopause, only to discover that at 42 she has finally become pregnant. Her husband Paul was about to leave her for Maggie, a younger woman he has been seeing. A baby seems to be the last thing they want, and Clair considers and almost has an abortion. Delivery is likely to be difficult and Dr. Welby even mentions the possibility of a "defective baby". This episode tells the story of how the older couple learns to cope, and hopefully will learn to love, their new child.

Actress Nadine Cabot suffers a cerebrovascular accident, more commonly know as a stroke, when a small aneurysm in her brain ruptures. Dr. Welby diagnoses her and gets her right to the hospital, but during the cerebral angiography she experiences another bleed, necessitating immediate surgery. Neurosurgeon Dr. Hoving does what he can, but he cannot completely seal off the defect, and Cabot awakens with certain deficits. Her husband and manager pushes her hard during her rehabilitation, but is he pushing her too fast? And why is his so insistent she work so hard? If he ...

Captain Rick Ballinger, retired Naval hero, has finally finished building his boat, and now plans to sail it back to the places he visited during his military service, bringing with him his son Sailor. But his shortness of breath, cough, and numbness of the hands suggest that may not be a good idea. Dr. Welby discovers from a blood examination that he suffers from pernicious anemia - a treatable disease if he's willing to follow a doctor's advice. Unfortunately, his pride goads him into making poor decisions that might cost him and his son their lives.

Dr. Welby helps a young, pregnant woman come to terms with her past - namely, a past relationship she had concealed from her husband. Her previous pregnancy was ended by abortion - after she develops complications late in her third trimester. When Welby tells the husband about his wife's past (she was just a teenager when she was pregnant before), the man is furious and wants to leave his wife, but Welby sets him straight.

A blind couple's relationship is tested when an operation restores the young man's sight and they have to reconcile their worlds.

An aging yet robust diver refuses to take Dr. Welby's advice to slow down after he's informed that he has emphysema.

Dr. Welby's girlfriend, Myra, takes a pregnant hippie into her home.

A young man named Scott Behrman, who has recently quit using LSD, bursts into Welby's clinic in a stupor. An after-effect of his withdrawal of the drug (which he started using to deal with family pressures and the death of his mother), Behrman will suffer several more of these "acid flashes," the tipoff to Welby that the young man may need more serious intervention to help completely heal him. However, Welby has to deal with Behrman's stubborn father who believes that, given a job with the family's warehousing business and a little love, the attacks will go away. It ...

A policeman who is up for a promotion wishes to keep his illness quiet, but Dr. Welby is unwilling to keep the ailment secret because it may hinder the officer in completing his duties.

Parents of a teenaged boy with leukemia refuse to allow Dr. Welby to inform him of his condition.

A priest friend of Dr. Welby's suffers severe asthmatic attacks due to pressure from his parishioners. The pressure increases when he is unable to restore an injured man's will to live.

A basketball player seeks out a faith healer for his injured knee instead of having the surgery Dr. Welby recommends.

Billy Kincaid is the son of prominent rights activist Sam. He is beaten a cop durin a non-violent student demonstration where he becomes Dr. Welby's patient. The doctor is accused of covering up for the policeman.

A diabetic threatens to stop taking his insulin shots to get even with his father, whom he blames for his mother's suffering.

Consuelo's mother is diagnosed with a malignant tumor, and although she accepts the doctor's diagnosis, she finds it hard to accept her roommate, a sour woman dealing with a heart condition.

A newly married man asks Dr. Welby to perform a vasectomy. The man believes he has Huntington's Chorea and fears passing the disease down to his children. Welby and Kiley calm the heartbroken wife while attempting to confirm the diagnosis.

While visiting a drug rehab clinic, Dr. Kiley is shocked to see that one of its patients is Mr. Chambers, who used to own an auto repair shop and gave Kiley his first job in order to save money to go to college. Chambers' life fell apart after his daughter was killed in a car accident--he lost his business, became addicted to heroin, turned to crime to support his habit and served a stretch in prison. Kiley is determined to help Chambers get his life back on track, but he runs into unexpected difficulties.

Dr. Kiley's old friend Dinty is a jockey endangering his life by abusing diet pills as a desperate measure to maintain an impossibly low weight.

Kiley undergoes a bout with chicken pox, and the young physician deals with an oil field worker who worries over the prospect of having bladder cancer.

Though she underwent a successful heart surgery as a young girl, a newlywed suffers heart seizures as an adult. Wanting a full life, she pushes the limits despite an overprotective husband.

An oceanographer diagnosed with caisson disease (aka "the bends") insists on one last dive, despite Dr. Welby's warnings that just one dive might kill him.

A hemophiliac begs Dr. Welby to keep his condition secret from his new schoolmates. Dr. Welby is concerned that he risks his health to achieve a normal teenage existence.

Dr. Kiley rescues a young boy with asthma and meets Enid Cooper, a compassionate counselor at an orphanage whose medicine cabinet suggests a dependence on prescription drugs.

Dr. Welby steps in to help a former classmate of Dr. Kiley's, a maverick young doctor who is fighting to keep his neighborhood clinic operational.