Necrotizing fasciitis (NF) is a severe soft tissue infection, which has a reported 25 per cent to 60 per cent mortality rate. In addition, NF has been reported to occur after invasive procedures. We present a 10-year retrospective study on postprocedural NF and its differences with community-acquired NF. A retrospective study was conducted from 1996 to 2006. Charts were searched using International Classification of Diseases, 9th Revision codes for NF and gas gangrene. Patients who developed NF in the area of their previous procedure without any other inciting cause of the NF were deemed eligible for the study. Eleven patients met eligibility criteria. Seven patients' initial procedures were elective, whereas four were semiemergent. The median age was 48 years (range, 24-81 years). The time between the initial procedure and operation for NF varied from 3 days to over 3 months. No single laboratory value helped in diagnosing NF. Sixteen different bacteria were isolated from the 11 patients. Ten of 11 patients required multiple debridements. There were four mortalities, three of whom had comorbidities known to predispose to infection. NF is a rare but serious complication after invasive procedures. As a result of important differences that exist between postprocedural and community-acquired NF, we propose that postprocedural NF should be classified in its own subcategory.