BACKGROUND/AIMS: Leukocytosis and hypoalbuminemia are known to be poor prognostic factors. The aim of this study was to determine how the leukocyte counts and albumin level are related to the colonic endoscopic findings. METHODS: Fifty three pseudomembranous colitis (PMC) patients confirmed by a lower endoscopy were analyzed. Endoscopic degree of pseudomembranous plaque was classified into four grades. The endoscopic severity was classified into two groups (group A: G I~II, group B: G III~IV). RESULTS: The mean age was 64.9 years, the mean onset of diarrhea after exposure to antibiotics was 12.9 days, the reasons for admission were medical (58.5%, 31) and surgical (41.5%, 22). Frequently the causative antibiotic was cephalosporin (81.1%, 43/53), and the mean WBC counts and albumin level were 13,045/mm3 and 3.13 g/dL, respectively. The endoscopic degrees of PMC was grade I (9.4%, 5), grade II (32.1%, 17), grade III (41.5%, 22), and grade IV (17%, 9). The patients' WBC counts and albumin level were not associated with the endoscopic severity. The age, gender, causative antibiotics, diabetes showed no correlation. CONCLUSIONS: There were no correlations between the known poor clinical prognostic factors (leukocystosis and hypoalbuminemia) and the endoscopic severity.