The best surgical option for the management of severe cases of Peyronie's disease is currently a matter of debate. To determine medium-term outcomes and complications after treatment of severe Peyronie's disease by porcine small intestinal submucosa (SIS) grafts, we retrospectively reviewed 33 consecutive plaque incisions followed by 4-ply SIS grafting in 28 patients (2002)(2003)(2004)(2005)(2006)(2007)(2008)(2009). Postoperative complications, penile length preservation, de novo ED, penile curvature correction and curvature recurrence rates were recorded. Median patient age was 54 years (38-69 years). Median preoperative curvature was 901 (30-901) (stable for at least 6 months). Six patients (21%) had preoperative ED. There were few postoperative complications (no cases of infection, haematoma (n ¼ 2), penile hypoesthesia (n ¼ 1), patch rejection and migration (n ¼ 1)). Subjective penile shortening and de novo ED were observed in 7 (25%) and 3 (11%) patients, respectively. The success rate for the procedure (straight penis or curvature p201 and ability to have intercourse) was 67% (22/33). Four patients achieved curvature correction after a repeat procedure with a new SIS graft. Eleven patients experienced recurrence within 3 months of surgery. After a median follow-up of 9 months (3-94), 22 patients (79%) had a satisfactory curvature correction.