The show focuses on a group of tenants in an office building located at 99 Sumach Street, Toronto.
Rosemary Radcliffe played the title character, aspiring Canadian documentary film-maker Rosie Tucker.
[2] The initial cast also includes Fiona Reid as Mona Swicker, an operator for the Ringading Telephone Answering Service; John Stocker as elevator operator Dwayne Kramer; Dan Hennessey as Ralph Oberding, salesman for the Neva-Rust Storm Door Company; Barrie Baldaro as Rosie's production assistant Dudley Nightshade; and Dan Aykroyd as building janitor/superintendent Purvis Bickle.
Aykroyd appeared as a regular in this series concurrently with his star-making turn on Saturday Night Live, which debuted less than a month after Coming Up Rosie.
Later cast members—replacing Aykroyd and Reid—included John Candy as Wally Wypyzypychwk, the Ukrainian owner of Sleep-Tite Burglar Alarms, and Catherine O'Hara as answering service operator Myrna Wallbacker.