Paraphimosis and penile prolapse have been described in hystricomorph rodents. Commonly the cause is a ring of fur or debris, found at the base of the penis, especially in chinchillas. Other causes described include infection, trauma and irritation. In dogs, preputial reconstruction is used to narrow the preputial orifice. In this case, a degu was seen for recurrent penile prolapse. An excessively wide preputial orifice was the presumptive aetiology. A simple surgical technique for prevention of persistent penile prolapse is described. The technique involves narrowing the preputial orifice without risking iatrogenic damage to the penis or urethra with a simple suture to approximate both sides of the mucosa on the ventral aspect of the distal preputial orifice. No recurrence or micturition problems were seen 18 months following surgery.