Monkhouse's adult career began as a scriptwriter for radio comedy in partnership with Denis Goodwin, a fellow Old Alleynian with whom he also compèred "Smash Hits" on Radio Luxembourg. Aside from performing as a double act, Monkhouse and Goodwin wrote for comedians such as Arthur Askey, Jimmy Edwards, Ted Ray and Max Miller. In addition, they were also gag writers for American comedians, including Bob Hope, when they wanted jokes for British tours. Indeed, when Goodwin broke up the partnership in 1962, it was to work for Hope.