Biomedical studies accompanied by a questionnaire survey were carried out on 803 pupils of classes 3, 5 an 7 attending 17 primary schools in the Kumba Health District to determine the prevalence of soil - transmitted nematodes and infection-associated morbidity. The prevalence rate of worms in the sample population from the questionnaire survey was 42.3% which correlates closely with 44.2% recorded for abdominal pains. The biomedical studies gave a worm infection rate of 67.1%. Ascaris lumbricoides, Trichuris trichiura and hookworm had prevalence rates of 54.9%, 33.8% and 20.3% respectively. Mixed infections were recorded in 34.4 % of the sample population compared to 32.8% for single infections. Hookworm infection rate was significantly higher in the rural areas than in the urban areas (27.5 % versus 14.8%, P < 0.001). A similar trend was observed for T. trichiura (38.4% versus 30.3 %, P < 0.02). Prevalence of A. lumbricoides was similar in the urban and rural areas (56.5% versus 52.6%). Males carried heavier burdens of Ascaris and Trichuris than females. The worm burden for all 3 species decreased as children moved to higher classes and with age after the first decade of life. There was a significant correlation between the intensities of infection of A. lumbricoides and T. trichiura.