Main Cast:
* Stephanie Cole as Sister Patricia "Patsy" Carpenter (1981-1984)
* Denholm Elliott as Dr. David "Dai" Evans (1981-1984)
* Lesley Dunlop as Sister Jean "Jenny" MacDonald (1981-1984)
* Judy Geeson as Sister Ann "Nancy" Nicholson (1981-1984)
* Cheryl Campbell as Sister Doreen "Dora" Lewis (1981-1984)
* Elizabeth Estensen as Sister Peggy "Peg" Sweeney (1981-1984)
* Stephanie Beacham as Sister Veronica "Ronnie" Miller (1981-1983)
* Juliet Mills as Sister Lily "Lillian" Dawson (1981-1984)
* Gwen Watford as Sister Barbara "Bobbie" Taylor (1981-1984)
* Patricia Quinn as Sister Margaret "Maggie" Ryan (1981-1983)
Notable recurring characters:
* Peter Bowles as Colonel "Big" John Caldwell (1982-1984)
* Christopher Timothy as Reverend Thomas "Tommy" Lloyd (1982-1984)
* Nicholas Clay as Captain "Jack" Carter (1982-1984)
* David Suchet as Dr. Charles "Charlie" Jones (1983-1984)
* David Robb as Dr. "Alan" James (1984)
Note: This list includes only some of the main cast members, and there were many other actors and actresses who appeared in smaller roles throughout the series.