A study was conducted among 2 500 secondary school students in Calabar, in order to determine the incidence of amoebiasis caused by Entamoeba histolytica. Microscopic examination of faecal sample smears showed higher percentage infections in the males than in the females; 61 out of 1 250 males were infected (4.8%), while 52 of 1 250 females were infected (4.1%). Among infected persons, asymptomatic carriers (64.6%) and symptomatic cases (35.4%) were recorded. Infection was lower among students using water flush toilet facilities than those using pit and bucket latrines. The infection was attributed to poor sanitation and inadequate health facilities.