 | Jason Robards Andrei Sakharov |
 | Glenda Jackson Yelena Bonner |
 | Nicol Williamson Malyarov |
 | Frank Finlay Kravtsov |
 | Michael Bryant Syshchikov |
 | Paul Freeman Pavel Leontiev |
 | Anna Massey Klavdia |
 | Joe Melia Sergej Kovalov |
 | Lee Montague Slavsky |
 | Jim Norton Roy Medvedev |
 | Valentine Pelka Efrem Sakharov |
 | Catherine Hall Tanya Sakharov |
 | John McAndrew Alyosha Sakharov |
 | Debbie Farrington Lisa Sakharov |
| David Midwinter Matvel Sakharov, age 10 |
| Craig Dickerson Matvel Sakharov, age 5 |
| Toni Warwick Anya Sakharov |
 | Eileen Way Ruf Grigorievna |
| Denyse Alexander Dr. Lydia |
 | Marion Bailey Ludmilla Kovalov |
 | Anton Lesser Valery Chalidze |
 | Norman Rodway Psychiatrist |
 | Elizabeth Spriggs Nobel Presenter |
| Robert Sherman American Reporter |
 | Paola Dionisotti Patient's Wife |
 | Avril Elgar OVIR Administrator |
 | Tenniel Evans Dean Fedorenko |
 | Jean Heywood Sakharov's Secretary |
 | Alex McCrindle Siberia Trainman |
| John Rowe Norwegian Diplomat |
| Jane Wood Witness at Trial |
| Ruth Goring Wedding Registrar |
 | Bernard Kay Prosecutor |
| David Landberg Reporter |
 | John Normington OVIR Clerk |
 | Olivier Pierre Reporter |
| Tony Sibbald Reporter |
| Martyn Whitby Mikhail |
 | John Boswall |
| Christopher Guinee |
| John Burgess |
 | Robert Gwilym |
| John Cording |
| Laurence Harrington |
 | Richard Cubison |
| Sarah James |
 | Alan David |
 | Ralph Nossek |
 | Ron Donachie |
| James Sport |
 | John Forgeham |
 | Vic Tablian |
| John Golightly |
 | Tom Wilkinson |
 | Derek Lyons Russian Guard (uncredited) |
