This is a review of existing data on the burden of shigellosis in Thailand to determine trends, vulnerable groups, predominant species and serotypes, and antimicrobial resistance patterns. Diarrhoea and dysentery morbidity and mortality data from 1991 to 1999 was collected from the routine surveillance system and demographic data from the government census. International and local literature published between 1988 and 2000 was systematically reviewed. Based on the routine surveillance system, the annual incidence of bacillary dysentery decreased from 1·3 to 0·2/10000 persons per year. The remaining burden is highest in children <5 years of age at 2·7/10000 persons per year. In comparison, a prospective study utilizing active surveillance found an incidence in children <5 years of age that was more than 100-fold higher at 640/10000 persons per year. Despite the decrease in morbidity and mortality based on routinely collected data, shigellosis remains an important problem in children <5 years of age in Thailand.