One fine day a wealthy young rich man named Bob Merrick (Hudson) is taking his boat out for a spin on Lake Tahoe. Bob, jetting across the lake at very high speeds, flips his boat. Bob nearly dies, but the timely arrival of a "resuscitator" from the nearby home of one Dr. Wayne Phillips saves Bob's life.
Unfortunately for Dr. Phillips, he has the bad timing to have a heart attack just as his resuscitator is away saving Bob Merrick's life. Consequently Dr. Phillips dies, and his lovely bride Helen Williams (Wyman) is left a widow. Dr. Phillips was a highly respected member of his community, and his friends and family are chagrined that he died so that a hard-drinking, hard-partying rascal like Bob might live.
Bob, who has continued to drink and party after his brush with death, rolls his car while driving drunk outside the home of Edward Randolph, a friend of the Phillips family. Randolph tells Bob that Dr. Phillips was a humanitarian and philanthropist who dedicated his life to others (to the extent that he left Helen broke due to giving the family fortune away). Bob resolves to make himself over and put this life philosophy into practice. He approaches Helen Phillips, but Helen, recoiling from the man she blames for her husband's death, runs right into a passing car. She is blinded. More melodramatic plot twists follow.
The second screen adaptation of Lloyd C. Douglas' 1929 novel of the same name (the first film version, made in 1935, starred Irene Dunne and Robert Taylor), Magnificent Obsession was a huge hit and the first major Hollywood success for Sirk, who spent the next five years putting out a series of similarly weepy dramas before retiring from filmmaking.
- Artistic License – Medicine: So a "lesion" and/or a "hematoma" suffered in a car accident can cause permanent blindness, hm?
- The Atoner: Bob eventually decides to remake his life and dedicate himself to others as Dr. Phillips did in order to repay his debt.
- Burn the Witch!: Symbolically! Bob and Helen stop into some idyllic Swiss town and discover a festival that involves the ritual burning of a witch made out of straw.
- Chick Flick: A typical example of the potboiler dramatic romances that Sirk specialized in.
- Downer Beginning: Helen Phillips comes home to find that her idyllic existence has been ruined by the sudden death of her husband.
- Driving a Desk: Used extensively, and especially noticeable when Bob and/or Helen are driving around Lake Tahoe.
- Establishing Character Moment: Insouciant, careless Bob ignoring the fear of his companion and shouts of warning from the lakeshore and revving his boat to still higher speeds.
- Fanservice: Did Bob really have to go into the OR shirtless?
- Foreshadowing: Later plot developments are made marginally more credible by Bob's comment early in the film that he studied medicine for a while before dropping out of medical school.
- Hangover Sensitivity: Bob is feeling the effects when he wakes up the next morning at Randolph's house after a drunken car crash.
- Land Poor: Helen is unpleasantly surprised to learn that Wayne's philanthropy and do-gooder instincts have left her with the lavish lake house and the hospital and an empty bank account.
- Melodrama: Hoo boy. Helen's husband dies and Bob wants to make amends but Helen gets in a car accident because of Bob and Helen is blinded so Bob courts her under a false name and they fall in love and Bob tells her who he really is but Helen already knows and Bob secretly saves Helen from bankruptcy and Bob sends Helen to Europe to get her blindness cured but the doctors can't cure it so Bob takes her on vacation and Bob asks her to marry him but Helen doesn't want people to pity her so she leaves Bob and then Bob goes to medical school and becomes a neurosurgeon but then Helen gets a tumor and Helen is going to die and Bob is the only doctor who can save her so he does and he cures her blindness in the process. Whew...
- Must Make Amends: Bob specifically helps out the Phillips family, making payments that are disguised as insurance settlements, and arranging for Helen to go to see European specialists who might be able to cure her blindness. He falls in love with her in the process.
- Paper-Thin Disguise: Bob introduces himself to a now-blinded Helen as "Robbie Robinson." When he finally confesses his identity Helen tells him she's known for a while.
- Smart People Play Chess: How the doctors while away break time at Bob's hospital.
- Spinning Paper: It isn't exactly spinning paper, but a hand flipping open a "Newsweek" magazine reveals that Bob has completed his education as a neurosurgeon and helped build a new neurosurgical center at an eastern hospital.
- Spiritual Successor: All That Heaven Allows, which reunited Sirk with Hudson and Wyman one year later.
- Time Skip: A period of several years pass after Helen abandons Bob, long enough for him to complete his med school studies and his specialty training as a neurosurgeon.
- Title Drop: Randolph calls the dedication of one's life to others a "magnificent obsession."
- Widow's Weeds: Helen is wearing the black dress and veil when she has her tragic meeting with Bob.