BACKGROUND The combination of perforated diverticulitis in a lumbar hernia constitutes an extremely rare condition. CASE PRESENTATION e report a case of a 66 year old Caucasian woman presenting with perforated sigmoid diverticulitis localized in a lumbar hernia following iliac crest bone graft performed 18 years ago. Emergency treatment consisted of laparoscopic peritoneal lavage. Elective sigmoid resection was scheduled four months later. At the same time a laparoscopic hernia repair with a biologic mesh graft was performed. CONCLUSION This case shows a very seldom clinical presentation of lumbar hernia. Secondary colonic resection and concurrent hernia repair with a biologic implant have proven useful in treating this rare condition.