We evaluated the UNICEF/Government of Egypt/WHO Schistosomiasis Control project in 2 districts of Beheira Governorate of the Nile Delta during 3 weeks in February 1988. The project, begun in 1983, was focused on reducing prevalence, intensity, and morbidity due to schistosomiasis by providing diagnosis and treatment with praziquantel to schoolchildren. Schools were visited twice. Following the completion of the school surveys, the program was extended into the community. Chemotherapy was delivered by mobile and static teams. The evaluation indicated that, with respect to accuracy of diagnosis, record-keeping, and coverage of targeted populations, project tasks were performed exceedingly well by highly motivated, well-supervised mobile teams. Static teams in rural health centers were less successful in providing diagnosis and chemotherapy to village populations. We resurveyed 6 randomly selected schools to assess the impact of chemotherapy. Overall, the prevalence of Schistosoma mansoni infection was reduced from 60.3% to 24.8% between the first and second surveys (∼1 year apart) and was still lower (41.1%) than initial levels up to 3 years after the last treatment with praziquantel. The percentages of those with ≥34 S. mansoni eggs/slide using the Kato-Katz technique showed a marked and prolonged decrease (17.1% to 0.3% to 2.2%). The prevalence of S. haematobium infection dropped from 37.6% to 5.5% and was still 9.9% at the time of the evaluation. The percentages of those with ≥50 S. haematobium eggs/10 ml urine dropped less dramatically (17% to 4.4% to 11.9%). Mobile teams conducting vigorous chemotherapy programs targeted at schoolchildren can have long-lasting benefits in terms of prevalence and intensity.