This study determines the association of Clotridium difficile and its toxin A with the histopathological damage in patients from the Gastroenterology Service of Victor Lazarte Echegaray Hospital, Trujillo-Perú from january to august, 2003. The study was done in 24 patients admitted with treatment of nosocomial diarrhea. Stool samples were colleted from each patient to diagnose C. difficile and its toxin A using a commercial kit (Oxoid). The evaluation histological of damage was made in each patients, the damage were typified in three types of lesions (I, II or III). It was found that 18 (75%) patients had C. difficile, but only 15 (62,5%) of them had toxin A in faeces and three (12,5%) did not have colonic lesion. The lesion type I, was the most predominant (37,5%). From nine patients without toxin A in faeces, one (4,16%) had C. diffficile and colonic lesion, by the other hand, two (8,33%) patients did not have toxin A and C. difficile but they had colonic lesion type I. It was not associa-tion between C. difficile and its toxin A. There is an important increase of C. difficile incidence. The presence of patients with C. difficile but without toxin A is explained by the existence of atoxigenic strains, being the lesions produce by several causes, not only by the presence of toxins.