This study aimed to assess the body image and quality of life of individuals suffering from gender dysphoria (GD) who were undergoing different types of treatment or no treatment at all. This was a descriptive-comparative study of 90 patients with GD sorted into three groups: untreated (no hormone therapy or surgery) (n = 30), hormone therapy (n = 30), and gender-reassignment surgery (n = 30). They were recruited using convenience sampling from a hospital in Tehran, Iran. The tools for data collection were three questionnaires to assess quality of life, body image, and demographic characteristics. The results showed that scores of quality of life and body image were significantly higher in the surgery group compared to the untreated singular (p < 0.001). A significant correlation was found between the quality of life and body image of the patients (r = 0.49; p < 0.001). We concluded that gender-reassignment surgery is the most effective treatment in improving body image and quality of life among individuals with GD.