Venlafaxine, which is often used for a number of psychiatric-related conditions such as the treatment of major depression, generalized anxiety disorder, social anxiety disorder and panic disorder, is generally a drug that is well tolerated and safe. The side effects of drugs can cause the treatment to prematurely terminate. Clinicians should prefer appropriate and low side-effects drugs to prevent this. This situation is also especially important for psychiatric patients. Prostatism, which impairs quality of life, is an important medical condition, with clinical and social implications. In the previous studies, prostatism was declared as a side effect of some antidepressant such as milnacipran, duloxetine and reboxetine. In our case, we discussed that venlafaxine-related prostatism developed in a male patient. As far as we know this is the first report of venlafaxine-induced prostatism.