The present study set out to test some of the predictions made by the Threat Simulation Theory, which suggests an evolutionary source of dreaming (Revonsuo, 2000a). The qualitative content and frequency of threatening events in dreams were compared between traumatized Swedish subjects with experience of the tsunami-disaster in Southeast Asia in 2004 with Swedish subjects with no traumatic experiences. Only a few of the hypotheses were supported by the results. The results and unsupported hypotheses are discussed with focus on the Threat Simulation Theory, and alternative explanations are considered.