Schistosomiasis is found in a significant proportion of returning travellers and immigrants to Britain. This study is a retrospective review of 1107 consecutive cases of schistosomiasis from Africa diagnosed by microscopy or serology presenting to the Hospital for Tropical Diseases, London, UK. 50.4% of cases were asymptomatic. The most common symptom which resolved on treatment was tiredness. Serology was positive in 951 (86%), and ova seen in 45%. Urine dipstick testing was positive for blood in 21% and protein in 15%, with eosinophilia in 44%. In this population urine dipstick, full blood count and serology were all insufficient screening tools used alone. Among patients with full follow-up data 3 months or more after treatment with praziquantel, definite treatment failure occured in 4 of 271 (1.5%), restricting the analysis to those with ova seen at diagnosis. There was no significant difference in treatment failure between 1 and 3 days of treatment. Antibody level was the same or higher than at treatment in 55% of cases seen after about 3 months and 38% after 1 year, confirming it is probably of limited clinical use in detecting treatment failure.