Among 810 parasitologically examined persons (1981) 277 (34%) showed positive findings. The high percentage of parasitisation in foreigners (86%) is to be explained by the in most cases aimed transfer of these patients (215 of the 810 persons). Affection with Schistosoma was recognized in 51 patients at the age of 17-47 years (means = 21.86), without Africans, and stood in the 3rd place of the distribution of frequency of the heterogeneous parasitoses. 49 of these patients came from Mozambique, 1 from Namibia and 1 from Zambia. In 51% S. haematobium was diagnosed, in 22% S. mansoni and in 27% a double infestation with the two forms of parasites. While 80% of the patients with affection of S. haematobium showed clinical symptoms (macrohaematuria, cystitis complaints), there were only 44% among the S. mansoni group. 47 patients were treated with Niridazole (Ambilhar, 25 mg/kg, 5-7 days), 2 patients with Praziquantel (Biltricide, 40 mg/kg, 1 day) and 2 other patients with Praziquantel after unsuccessful Niridazole therapy. Follow-up examinations were performed after 1, 3, 6 and 12 months. In 17% of the patients treated with Niridazole the primary treatment did not lead to cure; side effects (abdominal pain, nausea, vertigo) were observed in 55%. Praziquantel was tolerated very well. During a control period of 1 year living eggs of Schistosoma were no more proved.