Of 3250 diarrheal stools received for microbiologic diagnosis at a private clinical laboratory in Recife, Brazil, strains of Vibrio were isolated from 55 (1.7%). The study was carried out from May 1989 through May 1991. For recovering Vibrio, fecal samples were enriched in alkaline peptone water supplemented with 2% NaCl and subcultured on thiosulfate-citrate-bile salts-sucrose agar (TCBS). Of the recovered species, V. parahaemolyticus was most commonly found (24 strains), followed by V. furnissii (15 strains), V. cholerae non-01 (6 strains), V. alginolyticus (4 strains), V. fluvialis (2 strains), and Vibrio sp. (1 strain). The low isolation rate of Vibrio raises doubts about the cost-effectiveness of the use of TCBS in the routine enterobacteriologic workup of clinical laboratories