Schistosomiasis control operations carried out between 1983 and 1988 are described, together with information of the impact of schistosomiasis. The prevalence of schistosomiasis has declined from 9.5% in 1983 to 1.8% in 1988 (P<0.05). Bulinus truncatus, B. beccarii, and B. reticulatus wrighti are the intermediate hosts of S. haematobium in Saudi Arabia and are distributed unevenly in the different regions. Biomphalaria arabica is the intermediate host of S. mansoni and is found wherever the disease is endemic. The influx of expatriate workers from countries where schistosomiasis is endemic, inaccessible water sources, the constant movement of large numbers of bedouins in some regions, and manpower shortages in some regions are considered to be the main obstacles for schistosomiasis control programmes in Saudi Arabia. © 1990 The Society of Public Health.