The study assessed the efficacy of drug therapy on infection due to Schistosoma haematobium and associated indicators of infection among school children in Yewa North Local Government Area (LGA), Ogun State, Nigeria. Fresh mid-stream urine samples of 385 school pupils were screened for morbidity indicators (haematuria, protein, bilirubin, urobilinogen andleukocytes) of urogenital schistosomiasis and were further examined microscopically for ova of S. haematobium. A total number of 58 subjects randomly selected from the 226 infected population were followed up for 10 weeks post-treatmentre-assessment of morbidity. Chemotherapy resulted in reduced prevalence from 58.7% to 2.8% (p<0.001) 10 weeks post-treatment. Significant reductions in intensity of infection from 47.6 to 2.9 eggs/10 ml urine was also observed (p<0.001). All the indicators of infection tested also showed significant reduction (p<0.001) with the exception of proteinuria (p=0.422). Sustenance of treatment efficacy and reduced pathology will only be achievable in the area through integrated controlstrategies.