Aims: The aim of this study was to investigate the association between mental health and sociodemographic characteristics in services duty soldiers of a military base in Tehran, 2012-2013.Methods: This study was a cross-sectional study conducted on 102 soldiers. Data was collected by using the General Health (GHQ), and Socio-demographic characteristics questionnaires completed by a self-administration method. The general linear model was used to determine the socio-demographic predictors of mental health.Results: The mean (SD) total score of mental health was 26.2 (14.5) of the attainable score range of 0-84. In more than half of the soldiers (53.9%) according to the cutoff score of 23, the mental status was undesirable. The soldiers were scored worst in the anxiety and insomnia subscale [7.79 (SD)] and the best in the depression subscale [5.00 (SD)] of the attainable range from 0 to 21. In regards to the subscales of physical symptoms, anxiety and insomnia, social dysfunction and depression, respectively 5.9, 15.7, 3.9 and 9.8 percent of soldiers suffered from severe problems. The general linear model indicated that the survival status of parents and having a stepmother are considered to be a predictor of mental health (P<0.05).Conclusion: According to the results of this study, it is necessary to address the different levels of mental health in soldiers, providing counseling sessions and giving enough information for promoting their mental health.