• 
  Roland Joffé

  regizor

• 
  Paul Newman

  Leslie Groves
• 
  Dwight Schultz

  J. Robert Oppenheimer
• 
  John Cusack

  Michael Merriman
• 
  Natasha Richardson

  Jean Tatlock
• 
  Ron Vawter

  Jamie Latrobe
• 
  Clark Gregg

  Douglas Panton
• 
  Laura Dern

  Kathleen Robinson

• 
  John Considine

  Robert Tuckson
• 
  Fred Dalton Thompson

  Maj. Gen. Melrose Hayden Barry
• 
  Bonnie Bedelia

  Kitty Oppenheimer
• 
  Krzysztof Pieczynski

  Otto Frisch
• 
  Del Close

  Dr. Kenneth Whiteside
• 
  Walker Edmiston
• 
  John C. McGinley

  Capt. Richard Schoenfield, MD

• 
  Ed Lauter

  Whitney Ashbridge
• 
  Michael Brockman

  William 'Deke' Parsons
• 
  Joe D'Angerio

  Seth Neddermeyer
• 
  Alan Oppenheimer
• 
  Matthew Faison
• 
  Mary Pat Gleason

  Dora Welsh
• 
  Madison Mason

  Boris Pash
• 
  Todd Field

  Robert Wilson
• 
  Allan Corduner

  Franz Goethe (as Alan Corduner)
• 
  Jon DeVries

  Johnny Mount (as Jon De Vries)
• 
  Ron Frazier

  Peer de Silva