Roger Moore

as Lord Brett Sinclair/The General/The Admiral/Lady Agatha

Tony Curtis

as Danny Wilde/Aunt Sophie Schwartz

Bernard Lee

as Sam Milford

Reginald Marsh

as Dr Fowler

Tony Wright

as David Alton

Anne de Vigier

as Nurse Crane

Gerald Sim

as Dr Gordon

Johnny Briggs

as Charlie

Jeremy Burnham

as Scott Maskell

Joanne Dainton

as Miss Lindsay

Vivien Neves

as Danny's Girl

Diana Terry

as Brett's Girl

Diane Cilento

as Kate Sinclair

Denholm Elliott

as Roland

William Rushton

as Lance

Roland Culver

as Duke of Caith

Moultrie Kelsall

as Sir Angus

Christopher Sandford

as Onslow

Ivor Dean

as Mr Beebe