Twenty-two jirds, Meriones unguiculatus, were exposed to the bites of 2250 females of Aedes aegypti carrying an estimated total of 2464 larvae of Brugia malayi, and 13 jirds were offered for blood feeding to 1450 mosquitoes infected with about 4460 larvae of Brugia pahangi. On necropsy of the jirds, four months after feeding of the mosquitoes, a total of 88 adult filariae of B. malayi and 143 of B. pahangi were recovered in 20 and 13 jirds respectively. The majority of the adult filariae was obtained from the testes (48,9% of B. malayi and 53,2% of B. pahangi), from the heart-lung-system (26,1% and 45,6%), and additional in B. malayi from the tail (19,3%). It can be estimated that 3,6% (3,2%) of all infective larvae of B. malayi (B. pahangi), carried by Aedes aegypti females before feeding, reached maturity in the jird host after they had left the vectors during the blood meal. Microfilariae were found in the peripheral blood in seven of B. malayi infected jirds and in eleven of the jirds infected with B. pahangi.