Zbigniew Cybulski came to be known as the Polish James Dean. A lot of this stemmed from Andrzej Wajda's direction of the actor, both having seen Dean on screen. Wajda wanted Cybulski to emulate Dean's air of diffidence and apparent "non-acting" for Ashes and Diamonds.
René Clair was a particular fan of the film.
Citizen Kane - and Gregg Toland's cinematography in particular - was a huge influence on Andrzej Wajda at the time. Like Toland, the first thing the film's cinematographer 'Jerzy Wojcik' did was convince production designer Roman Mann to include ceilings in all the sets.
After the film's release, sales of sunglasses shot up because Zbigniew Cybulski wore them consistently throughout the film.
Because of the film's nihilistic tone, the Polish authorities were not keen on it being exhibited outside of the country. Until a low-level official had a print shipped out to the Venice Film Festival where it played to great acclaim.
Director Andrzej Wajda realized that his leading man Zbigniew Cybulski would be constrained by period costume so he allowed him to wear clothes that felt more natural to him.
One of Martin Scorsese's favorite movies. He showed it to Leonardo DiCaprio while making The Departed, as main characters of these two movies have to deal with the same dilemmas.
The entire film takes place over two days, May 8th and 9th 1945.
The title comes from a 19th century poem by Cyprian Kamil Norwid and references the manner in which diamonds are formed from heat and pressure acting upon coal.
Wajda was particularly influenced by The Asphalt Jungle.