Background Solid organ transplant (SOT) recipients carry a high risk of developing Clostridium difficileassociated colitis (CDAC) and an increased risk for recurrence.Patients and methods Between December 1996 and September 2007, a total of 227 patients with CDAC were identified when querying our institutional surgical infection database. This included 169 nontransplant patients and 58 SOT recipients, including 1 cardiac, 19 renal, 2 pancreas, 5 renal/pancreas, and 31 liver recipients.Results Overall, we recorded 556 infectious episodes at any site in the 227 patients analyzed who eventually developed CDAC (2.4 episodes/patient); the total number of CDAC episodes was 255: 204 patients had a single episode and 23 patients had multiple episodes of CDAC.There were 19 patients with two episodes, 3 with three episodes, and 1 with four episodes. Of the 23 patients with recurrent CDAC, 11 (48 %) were SOT recipients. A total of 19 % of SOT recipients had recurrent CDAC as compared with only 7 % for nontransplant patients (p = 0.0197). Time to first CDAC recurrence was a median of 58 (range, 17-1372) days for SOT recipients and a median of 30 (range, 6-108) days for nontransplant patients (p = 0.047).Conclusions SOT recipients at our institution were found to be a high-risk group for CDAC and had an almost threefold risk for recurrent disease. Double-drug coverage, extended application of metronidazole, and profound reduction in the level of immunosuppression may help to cope with this emerging problem.