While shopping in the Little Tokyo district of Los Angeles, she was discovered by talent agent Fred Ishimoto, which led to her film debut in The Geisha Boy (1958). In 1960, she appeared in the comedy film Wake Me When It's Over (1960). She starred with Lloyd Bridges in a 1959 Sea Hunt television episode as a Hawaiian woman fighting to protect pearl-beds from poachers. In 1962 she appeared in the television series Wagon Train in the episode "The John Augustus Story" as Mayleen. For the next decade, McCarthy continued acting, appearing in smaller roles in a number of films as well as guest spots on television, including the title role in the 1960 episode "Princess of Crazy Creek" of the syndicated western series Pony Express, starring Grant Sullivan. In 1961, she appeared as Haru in the Laramie series episode "Dragon at the Door". She also appeared in the ABC adventure dramas Adventures in Paradise and The Islanders, both set in the South Pacific. During this time she made two guest appearances on Perry Mason: in 1959 she played defendant Mitsou Kamuri in "The Case of the Blushing Pearls," and in 1965 she played Sally Choshi in "The Case of the Wrongful Writ." She also guest starred on ABC's The Bing Crosby Show in the 1964-1965 season. She starred with Robert Conrad in the final episode of the First Season of The Wild Wild West, dated April 22, 1966 "The Night of the Sudden Plague" as a Chinese woman "Anna Kirby", who is the daughter of a mad professor breeding bacteria for a serum that causes temporary paralysis. She also made appearances in The Man From U.N.C.L.E., Hawaii Five-O and Love, American Style.