Introduction: Both at the 11th edition of the international classification of diseases (ICD-11) and in the Fifth edition of the diagnostic and statistical manual of mental disorders (Fifth edition-DSM-5), It has been noted that the attitudes (toward self, others, world and future) and quality of sleep can be seriously impaired by post-traumatic stress disorder (PTSD). The present study was conducted to compare hostility and sleep disorders among nursing students with and without PTSD. Materials and Methods: This descriptive-comparative causal study was performed on 190 (140 females & 50 males) nursing students from Islamic Azad University, Toyserkan, Iran. Participants were chosen by stratified sampling. Three questionnaires were used in this study, including the Post-Traumatic Stress Disorder Checklist-Civilian version (PCL-C), hostility subscale from Buss & Perry aggression questionnaire, and sleep disorder subscale from Mississippi scale for combat-related PTSD. Results: Fifty-six out of the 190 students were identified with PTSD symptoms. This group of students had significantly higher scores on hostility and sleep disorders. Regression analysis indicated that sleep disorders and hostility were strong positive predictors for PTSD. Conclusion: Due to considerable prevalence and impact of PTSD on sleep quality and hostility in patients who suffering from PTSD, intervention to promote appropriate diagnosis and treatment seems to be crucial.