Clostridium difficile-associated disease can be observed especially in hospitalized patients who use broad-spectrum antibiotics. The aim of this study was to investigate the presence of C.difficile as the causative agent of diarrhea in outpatients and inpatients. During January-December 2005, 45 outpatients and 46 inpatients (of them 11 were intensive care unit patients) who had developed diarrhea due to antibiotic use, were included to the study. In addition 7 intensive care unit personnel and 20 food handlers were also included to the study in order to detect their carrier states. The age range of patients was 16-80 years, and of them 45 (49.5%) were male, while the age range of the personnel was 25-55 years, and of them 21 (78%) were male. Stool samples collected from the study groups were cultivated in C.difficile agar media (C.difficile Agar Base, Oxoid) as well as on routine bacteriologic media, and C.difficile growth was confirmed by latex agglutination test with the use of specific antisera. The presence of C.difficile toxin A was investigated by latex method (Oxoid, UK), and toxin A and B was searched by enzyme-linked immunoassay (ELISA; Seramun GmbH, Serazym C.difficile Toxin A+B), in the stool samples. While C.difficile was isolated from 13 (14.3%) of the 91 samples, no positive result was detected in the personnel. There was no statistically significant difference between outpatient and inpatient groups by means of C.difficile culture positivity (15.5% and 17.1%, respectively) (p > 0.05). All of the culture positive samples were also found positive by ELISA Toxin A+B method (100%), but only 4 of them (30.7%) yielded positive result by Toxin A latex test. It was detected that 84.6% (11/13) of the patients had used ampicillin/sulbactam, 7.7% (1/13) used cotrimoxazole-SXT, and 7.7% (1/13) used macrolide antibiotics. The use of ampicillin/sulbactarn was found statistically significant in development of diarrhea (p < 0.05). Our data indicated that ELISA Toxin A+B is a reliable method with 100% specificity and sensitivity in the rapid diagnosis of C.difficile until the culture results were obtained, however, although specificity of Toxin A latex test is 100%, its use alone as a primary rapid diagnostic test was not recommended because of its low (30.7%) sensitivity.