In the differential diagnosis of perineal cystic lesions, a wide range of lesions can be considered, but perineal epidermoid cyst is rare. We present a case of perineal epidermoid cyst, a man with a complaint of painless perianal mass who appeared at the general surgery clinic. Ultrasonographic and conventional magnetic resonance imaging (MRI) findings are noted along with the diffusion-weighted MRI findings. To our knowledge, there has been no specific study in the literature up to now focusing on the value of diffusion-weighted MRI findings in the differential diagnosis of perineal cystic lesions; this technique may be useful.