After the initiation of residual house spraying with DDT in 1953, populations of Anopheles culicifacies Giles in the province of Helmand decreased and remained at a low level for ca. 15 yr. In 1968 and the following years the number of cases of malaria increased considerably, and epidemics appeared in 1970. Susceptibility tests showed that Ae. culicifacies is resistant to DDT but susceptible to dieldrin and malathion in Helmand.