The use of pyrantel pamoate in controlling soil transmitted helminthic infection has been studied in a sample of population on low socio-economic level, consisting of workers of the Madukismo Suger Estate and their families. Pyrantel pamoate proved to be more effective to Ascaris lumbricoides and hookworm than to Trichuris trichiura infection. The cure rates found were 90.2%, 57.5% and 3.7% for A. lumbricoides, hookworm and T. trichiura respectively, while in the hookworm infection the drug was more effective to Ancylostomiasis duodenale than to Necator americanus. The result of the study showed, that 6 months after treatment was still found a reduction of the prevalence of A. lumbricoides infection to 27.2% (from 74.4% to 47.2%) and a reduction of the egg count from 6352 to 3348 per gram of stool. After one year the prevalence rate and the intensity of Ascaris infection reached almost the same level as that before treatment. As regards the hookworm infection, it seemed that the treatment was still effective after a period of one year. Prior to the treatment the prevalence rate was 36.3% and the egg count was J37 per gram of stool, while one year after treatment they were still reduced to 23.97c and 39 respectively.