Detailed studies were carried out to assess the infection characteristics of the antelope schistosomes in BALB/c mice and Mastomys coucha. Both schistosome species reached sexual maturity in these hosts. However, they differed markedly in terms of egg production rates and preferred sites of tissue egg deposition. Tissue egg deposition commenced between 4 and 5 weeks in the case of Schistosoma margrebowiei and between 6 and 7 weeks in the case of S. leiperi. Tissue egg accumulation rates of S. leiperi were calculated to be 334 and 311 eggs/gravid worm pair/day in mice and M. coucha, respectively. The fecundity of S. margrebowiei was found to be substantially greater (approximately 5 times; daily output ranging from 1600–1900 eggs/gravid worm pair). While S. leiperi infections remained relatively stable in both hosts during the study period (i.e. up to 15 weeks after onset of egg laying), S. margrebowiei infections were observed to deteriorate rapidly in M. coucha.