The Egyptian skinks Mabuya quinquetaeniata were investigated for haemogregarines. The intracellular parasites were found in three developmental forms; trophozoite measured 4 µm; the intermediate form (a newly formed gamont) measured 14 µm and the elongated crescent-shaped one that measured 18 µm and considered as a mature gamont. Meronts were found only in the parenchyma cells of the liver of the infected skinks. The merogonic process began when the free parasites invaded the parenchyma cells, then they became more rounded or oval and began to grow in size. Meanwhile, the parasitophorous vacuole appeared enclosing the parasite and grows in size during the growth of the meronts. The formation of merozoites occurred by ectomerogony. The areas of the surface, overlying the peripheral nuclei, soon become elevated. At a later stage, these elevations become more prominent forming a conical protruding merozoite anlage, which contains tubular structure at the apical pole indicating the formation of the conoid. Moreover, they form subpellicular microtubules, rhoptries, micronemes, mitochondria and also Golgi apparatus. The cytoplasm remaining, after the separation of the merozoites, constituted the residual body, which decreased with the progress of the merogonic phase. The present meronts were found in two forms; the first form (macromeront) measured 18×12 µm and produces about 43 micromerozoites, each measured 13 µm. The second one (micromeront) measured 9×7 µm and producing 11 macromerozoites, each measured 17 µm. On the ultrastructural level, each parasite has a pellicle, which consists of outer and inner membranes, conoid, rhoptries, few micronemes and some of dense bodies.