Two sexually intact adult male chinchillas were presented with a swelling in the perineal region. Radiographically both masses had a soft tissue opacity. Ultrasonography confirmed the tentative diagnosis of perineal hernia. In the first case the ultrasonographic examination revealed a fluid-filled structure inside the swelling, which was determined to be the urinary bladder. In the second case the hernia sac was filled with homogeneous tissue, belived to be fat. Subsequently, unilateral perineal herniorrhaphies including an internal obturator muscle flap transposition technique were performed. Both chinchillas recovered well with subsequent uneventful healing of the surgical sites. No long-term complications or recurrences of the perineal hernias were reported. This clinical report shows that perineal hernias occur in chinchillas and can be surgically treated with success.