Patients with complicated diverticulitis rarely present with extraperitoneal manifestations but the manifestation of subcutaneous emphysema appears even more seldom. We present the case of a patient with a history of diabetes and immunosuppression, who was admitted with sepsis in association with cellulitis and subcutaneous emphysema of the left groin. The absence of peritonism due to corticosteroid treatment, a history of a recent fall with an ilio- and ischio-pubic fracture and subcutaneous emphysema led to a delay in the diagnosis. The final diagnosis was a perforated diverticulitis in a patent inguinal canal, which was only revealed after surgery. The various complications of diverticulitis, including extraperitoneal manifestations, and associated microorganisms implicated in cellulitis and subcutaneous emphysema are briefly reviewed.