Bacterial diarrheal diseases cause substantial morbidity and mortality in sub-Saharan Africa, but data on the epidemiology and antimicrobial susceptibility patterns of enteric bacterial pathogens are limited. Between May 1997 and April 1998, a clinic-based surveillance for diarrheal disease was conducted in Asembo, a rural area in western Kenya. In total, 729 diarrheal specimens were collected, and 244 (33%) yielded ⩾1 bacterial pathogen, as determined by standard culture techniques; 107 (44%) Shigella isolates, 73 (30%) Campylobacter isolates, 45 (18%) Vibrio cholerae O1 isolates, and 33 (14%) Salmonella isolates were identified. Shigella dysenteriae type 1 accounted for 22 (21%) of the Shigella isolates. Among 112 patients empirically treated with an antimicrobial agent and whose stool specimens yielded isolates on which resistance testing was done, 57 (51%) had isolates that were not susceptible to their antimicrobial treatment. Empiric treatment strategies for diarrheal disease in western Kenya need to be reevaluated, to improve clinical care