In the present study, the developmental stages of the life cycle of Isospora pardali sp. nov. were described for the first time from the leopard fringe-fingered lizard, Acanthodactylus pardalis in Egypt. Exactly 135 lizards were collected from South Sinai from October 2012 to December 2014 and examined for the presence of coccidian parasites. Oocysts were shed unsporulated, in early stages of sporulation and rarely sporulated. Events of sporulation and sporulation time were described for unsporulated oocysts. The infection rate was 37%. The sporulated oocysts were subspherical to ovoid measuring 22.6-26.8 x 22.3-24.6 μm and limited by a smooth double-layered wall; no micropyle, polar granule or oocyst residuum was observed. The sporocyst measured 10.6-14.4 x 8.6-9.6 μm with a sporocyst residuum; stieda and substieda bodies were observed. Experimental inoculation of sporulated oocysts was carried out and the developmental endogenous stages (merogony and gamogony) were followed up and described. The prepatent period was 4 days, while the patent period was 8-10 days. Endogenous stages took place in the lamina propria, enterocytes of small intestine and the liver of the experimentally infected lizards. Merogony occurred at 25-60 hours post inoculation and two generations were observed. The mature meronts measured 5.9-12.8x 3.8-12 μm and yielded up to 30 merozoites. Gamogony occurred at 72-96 hours post inoculation. The mature microgamonts measured 7.1-10.1 x 6.3-6.5 μm and contained up to 30 small nuclei, while the mature macrogamonts measured 12.2-18.8 x 12-12.6 μm and contained the two types of wall-forming bodies. At 90-96 hours post inoculation, newly-formed zygotes or young oocysts were observed.