The susceptibility of Arvicanthis niloticus, Mastomys huberti, Mastomys erythroleucus and Mus musculus was studied to assess the capacity of these rodents to transmit Schistosoma mansoni. The susceptibility was determined by the percentage of adult schistosomes recovered, the number of eggs per gramme of faeces, the viability of these eggs and the capacity of the rodents to maintain the life cycle of Schistosoma mansoni. The percentages of adult worms recovered were respectively 18%, 11.5%, 8.4% and 20.5% in A. niloticus, M. huberti, M. erythroleucus and M. musculus. After infection, they liberate in the environment viable eggs whose miracidia are infectious for the intermediate host (Biomphalaria pfeifferi). The mean egg load was 300 +/- 327.8 in A. niloticus; 664 +/- 673.5 in M. huberti; 240 +/- 304.8 in M. erythroleucus; 400 +/- 361.5 in M. musculus.