Posttraumatic symptoms, including nightmares, are more prevalent in World War II survivors than in the general population, but how war experiences have affected subsequent dream content in specific survivor populations remains less explored. In the present study, we used self-reports collected in 1973 from Polish Auschwitz survivors (N = 150; 45 women) to investigate the prevalence of posttraumatic symptoms, classified according to the DSM-5 diagnostic criteria for posttraumatic stress disorder (PTSD). Furthermore, we classified main themes, central emotions, and threatening events in the dreams (N = 632) of the survivors, comparing dreams recalled from before, during, and after the war. Of the respondents, 12.7% described experiencing all diagnostic criteria for PTSD. War-related themes were less common in dreams dreamt before than during the war but were most common after the war. Themes related to family and freedom were most likely to appear in dreams dreamt during than before or after the war. The most often occurring emotion was fear, and dreams from after the war were likely to contain more negative and less positive emotions than dreams dreamt during the war. The likelihoods of reporting threatening events and threats involving aggression were higher in dreams dreamt during than before the war and in dreams dreamt after than during the war. In conclusion, PTSD symptoms were common in Polish Auschwitz survivors 30 years after World War II, and the themes, emotions, and threatening events in their dreams seem to reflect lifelong posttraumatic dreaming. We interpret the results as lending support for the threat simulation theory of dreaming.