Chad Gates (Elvis Presley) returns to Honolulu after a two year spell in the army determined not to do what his mother wants, which is to take a job in the family pineapple business, settle down and marry a girl of his own social status.

He takes a job with a tourist agency where his half-French, half-Hawaiian sweetheart, Maile (Joan Blackman) works, and his first assignment is escorting a group of four school girls, chaperoned by their teacher, Abigail Prentice (Nancy Walters), around the islands.

After making arrangements to start the tour the next day, Chad takes Maile to a "welcome home" party at his house. His father, Fred (Roland Winters), and Jack Kelman (John Archer), Fred's boss and an old family friend, greet Maile cordially, but his mother Sarah Lee (Angela Landsbury), openly resents her presence.

Legend: Elvis and Joan Blackman.

The party starts to sag and Chad asks the four musicians, who are his beach boy pals (hired as a special concession to him), to step up the tempo. Soon the place is jumping. Chad and Maile do a number with the band and Sarah Lee obviously out of tune with the sound of "Youth", suffers a near collapse.

The following morning Chad takes the school girls on a scenic drive. Three of them are nice, normal teenagers, but the fourth, Ellie (Jenny Maxwell), is spoiled. She is consistently rude to Chad. But that night, at a hukilau, she suddenly changes and kisses him. She then becomes furious when he calls her a youngster and tells her to behave.

Although Chad's parents disapprove of his new job, Kelman admires his drive and accompanies him, a few nights later, to a luau. There, Chad introduces him to Abigail. Ellie, meanwhile, has begun to flirt with a tipsy tourist (Steve Brodie). When the latter stars to respond, Chad breaks it up and a fight ensues. Chad is put in jail. After is bailed out by his father, he is fired by the tourist agent. Blaming the row on the company he is keeping, his parents insist he gives up Maile. But he refuses and leaves home.

Abigail then hires him to take her party to Kauai. That night, after a day's sightseeing, Ellie comes to his hotel room and makes advances to him, just as his phone rings. It is Maile, who has just arrived with Kelman. Chad tells her that he will meet her in the lobby. But before he can get rid of Ellie, two of the other girls come looking for her and Ellie confronts them with a "so what" look.

A showdown is postponed by a rap on the door, it is Abigail. Chad tells the three girls to leave by the back door, then lets her in. She is in a esctatic mood. She confesses she came to Hawaii seeking romance and thinks she's found it. Believing she means him, Chad tries to get her to lower her voice by moving close to her. Ellie, watching outside the window, misinterprets his intention and runs away sobbing, followed by the other girls. And Maile, tired of waiting, walks to his room and sees Abigail there. See, too, misunderstands the scene and flees to her room.

The two girls return to Chad's room and tell him Ellie has driven away in a jeep. He follows her in another car, and finds her wading into the sea not far from her car, which is wrecked. After making sure she's not hurt, he gives her a lecture and a spanking.

The next morning, Maile avoids Chad, who is avoiding Abigail. But the latter corners him and finishes what she tried to tell him the night before, that she's in love with Kelman, Chad happily tells Maile, who after some first doubts, eventually believes him.

When they all return to Honolulu, Chad sells his father, with a little help from Kelman, on the idea of holding the next convention of mainland employees of his company on the island. The tourist agency he plans to open with Maile will handle all the arrangements after, of course, they get married. Which they do, in a colourful boat wedding ceremony which even Sarah Lee is proud to attend.