Epidermoid cysts are intradermal lesions that are frequently asymptomatic and can be found in any part of the body. The common sites of presentation in descending order of frequency are head, neck, trunk, extremities and the scalp. Here, we present the diffusion weighted magnetic resonance imaging (DW MRI) and ultrasound (US) findings in a 20 year-old female patient with perineal swelling, diagnosed on histological examination as a perineal epidermoid cyst. This location is rare for this type of cyst and there are limited reports, especially using the DW MRI technique.