Background: Trichomonas vaginalis infection is one of the most common sexually transmitted diseases in humans. T. vaginalis is a parasitic protozoan with a predilection for human urogenital tract and causative agent for vaginitis, cervicitis and urethritis in females. T. vaginalis infection is associated with risk of Human Immunodeficiency Virus infectivity and pregnancy complication. Objective: In this study, the prevalence of T. vaginalis in individuals who referred to public health units in Kashan city, Iran was investigated. Materials and Methods: This study was conducted on 970 women and 235 men who referred to 5 government health centers in Kashan, Iran during October 2012 to August 2013. Demographic information was collected as per the study protocol. Vaginal discharges and urine samples were obtained and examined by Trypticase-Yeast Extract Maltose (TYM) culture medium and wet-mount methods. The prevalence of T. vaginalis was determined using culture based method and wet-mount examinations. Results: The overall prevalence of trichomonal infection was 2% (95% CI, 2±0.08). The age of infected individual was 33.7±9.4 years. All of those infected, were married housewives and 58.3% of them had primary school education. No statistical correlation was observed between clinical manifestations and parasitological results (p=0.8). Conclusion: This study showed a relatively low prevalence of T. vaginalis infection in the study population. Since the clinical signs of trichomoniasis are the same of other Sexually Transmitted Diseases (STDs), confirmatory laboratory tests are necessary. Due to adverse outcomes of disease, there is a great need for public education regarding implementation of personal hygienic measures and prevention of inappropriate sexual contacts.