The epidemiological, clinical, and bacteriological aspects of shigellosis were studied in a population of hospitalized children in northern Israel. During the 6-year period 1987-92, 262 children were hospitalized due to shigella infection. Shigellosis represented 10% of pediatric admissions for diarrhea. Admissions for the disease peaked during the summer and autumn. The median age of the patients was 3 years. Shigella sonnei was isolated in 74% of patients and S. flexneri in 21% compared with relative frequencies of 87% and 10% respectively, in the non-hospitalized population of the area, detected during the same period (p < 0.001). Shigella sonnei represented 82% of isolates of hospitalized Jewish patients but only 60% of hospitalized Arab children, many of whom live in poverty and overcrowding (p < 0.001). Shigella flexneri was particularly frequent among hospitalized infants, and was associated with Arab origin, large families and residence in agricultural settlements. Duration of hospitalization was 4.7 ± 2.3 days for S. sonnei infections and 5.8 ± 3.6 days for S. flexneri (p < 0.005). No cases of shigella sepsis, hemolytic uremic syndrome, or fatalities were observed. Overall, 37% of all shigella isolates from hospitalized children were resistant to ampicillin, 71% to cotrimoxazole, 28% to both and 13% were resistant to ≥3 different drugs. It is concluded that shigellosis is an important cause of hositalization in northern Israel. Resistance to antimicrobial drugs is widespread among all Shigella spp. Although S. sonnei is the most common species, S. flexneri is particularly frequent in infants.