pipiens and C. quinquefasciatus femals infected with Hepatozoon sp. Present in the Saudi lizard Uromastyx microlepis were examined for sporogonic development. Mature zygotes formed synchronously at 8 hr then quickly subsided in C. pipiens. In C. quinquefasciatus zygote formation was more protracted and its density peaked at 12 hr. losses in parasite abundance during the conversion of zygote to oocyst was non significantly higher in C. pipiens than that in C. quinquefasciatus (P>0.05). melanotic encapsulation of oocysts was not observed for both mosquito species. On the 20^th day sporozoites were present in the salivary glands of C. pipiens while C. quinquefasciatus showed sporozoite- negative glands. Nearly half of mosquitoes with mature oocysts gave rise to sporozoite infected one. Parasite populations were not normally distributed in either mosquito species but were described by a negative binomial type of distribution.