Thelandros aegypti (Nematoda: Pharyngodonidae) isolated from the large intestine of the Egyptian spiny−tailed lizard, Uromastyx aegyptia, in North Sinai deserts, Egypt were described by means of light microscopy as a first description from this host in Egypt. 18 out of 25 (72%) of the examined specimens were naturally infected. The recovered nematodes characterized by the followings; the mouth bounded by three bilobed lips, the presence of three pairs of caudal papillae in male, the absence of gubernaculums, the post−equatorial vulva and the tail of female was suddenly constricted behind anus to form a terminal spike. Male was cylendrical with distinct posterior truncation, 3.0 (2.71-3.7) mm long; 0.24 (0.20-0.33) mm wide. Three pairs of anal Papillae were recorded; the first and the second were pre and perianal and the last pair immediately behind the rounded posterior region of the worm. The tail was narrow, sharply pointed and measured 0.052-0.072 mm in length with selender spicule measured 0.045-0.077mm long. Female was 4.34 (3.32-4.73) mm long, 0.29 (0.24-0.39) mm wide, vulva was post-equatorial, ovary was amphidelphic, the anterior part extended to the level of excretory pore and the posterior ovary extended posteriorly to the anal opening. Uteri were divergent. Egg was oval, slightly flattened and measured 65.4-79.2 μm long and 44.3-74 μm wide. The described parasite was compared with different species of the same genus from different hosts. It was found that morphometrically, the present species was more or less different from the comparable species and the only morphologically similar species was Thelandros aegypti.