Incubation in buffer of Bdellovibrio bacteriovorus 109J, B. stolpii UKi2, or B. starrii A3.12 with washed eucaryotic animal cells (mouse liver, hamster kidney, or bovine mammary gland) resulted in neither attachment nor growth of the bdellovibrios. When cells of these bdellovibrio strains were incubated with erythrocyte suspensions (bovine or rabbit) a very low level of bdellovibrio attachment and penetration occurred, but no growth could be detected. Using micurgical procedures, bdellovibrios were injected into the perivetelline space or the cytoplasm of rabbit ova. After 18–24h incubation, neither a significant loss nor increase of injected, intracellular bdellovibrios was observed. Limited axenic growth of bdellovibrios (109J or UKi2) occurred in media containing rabbit ova extracts and dilute nutrient broth. It is concluded that eucaryotic rabbit ova do not provide a suitable environment for intracellular bdellovibrio growth.