Objective: Nightmares are among the most frequent and disturbing symptoms of posttraumatic stress disorder (PTSD). However, basic research questions regarding key associations between certain nightmare characteristics, especially replicativeness, and posttraumatic psychopathology need further empirical elaboration. Method: Sixty-two German soldiers (mean age 33.8 years, 17.7% females) admitted to a hospital-based treatment program for veterans completed extensive assessments consisting of clinical interviews and self-rating measures with respect to sociodemographic characteristics and psychopathology as well as dream-related variables. Results: Although nightmare distress, frequency, and replicativeness were all linked to PTSD symptomatology, only the latter proved to be a significant predictor of PTSD diagnosis. Moreover, none of these nightmare characteristics predicted a depression diagnosis. Conclusions: The replicativeness of nightmares appears to be a key variable for understanding the relationship between posttraumatic nightmares and PTSD, whereas nightmare frequency and distress appear to be more aptly defined as generic markers of mental health.