Hayley Mills as Ellie Thomsen

Hywel Bennett as Michael Rogers

Britt Ekland as Greta

Per Oscarsson as Santonix

George Sanders as Andrew Lippincott

Aubrey Richards as Dr. Philpott

Ann Way as Mrs. Philpott

Patience Collier as Miss Townsend

Peter Bowles as Reuben

Lois Maxwell as Cora

David Bauer as Uncle Frank

Helen Horton as Aunt Beth

Madge Ryan as Michael's Mother

Windsor Davies as Sgt. Keene

Walter Gotell as Constantine

Geoffrey Chater as Coroner

David Healy as Jason

Robert Keegan as Innkeeper

Robert A. O'Neil as Broker

Mischa De La Motte as Maynard

Nicholas Courtney as Second Auctioneer (uncredited)

Leo Genn as Psychiatrist (uncredited)

Charlie Gray as Man at Auction (uncredited)

Victor Harrington as Man at Auction (uncredited)

Stephanie Mildenhall as Child (uncredited)

Jim Brady as Workman (uncredited)

Joe Phelps as Police Officer at Inquest (uncredited)

Ewan Roberts as Customer at Petrol Station (uncredited)

Reg Thomason as Doctor in Rembrandt Painting Mock-up (uncredited)

Steven Wallen as Young Michael (uncredited)

Russell Waters as Waiter (uncredited)