From January 1999 through December 2000, a total of 111 cases of Plesiomonas shigelloides infections were diagnosed in a medical center of northern Taiwan. The patients ranged in age from 22 days to 72 years. One third (39/111, 35%) of the positive cultures were found in young children (<2 years old). There was no significant difference in the incidence between males (56/111, 50%) and females (55/111, 50%). The peak seasons for the disease were summer (45/111, 41%) and autumn (42/111, 38%). The major clinical presentations in children were diarrhea (66/69, 96%) and fever (38/69, 55%), whereas diarrhea (41/42, 98%) and abdominal pain (30/42, 71%) were the most common presentations in adults. Most adults with P. shigelloides infection visited the emergency room (38/42, 90%) and received empirical antimicrobials (37/42, 88%), whereas children were more likely to be treated as outpatients (53/69, 77%) and inpatients (27/69, 39%). One third (23/69, 33%) of pediatric patients had mixed enteric infection, and 74% (17/23) of them were younger than 2 years. Salmonella species (17/24, 71%), especially group B Salmonella (12/17, 71%), were the most common mixed enteric pathogen. The disease is usually mild and self-limited. Symptomatic management is adequate and antimicrobial therapy is seldom required.