A new trematode species Sclerodistomum aegyptiaca (Hemiuroidea, Sclerodistomidae) was isolated from (50%) out of 120 (50 males and 70 females) Brushtooth Lizard fish collected from the Suez Gulf, Red Sea. Females fish were more infected (64.3%) than males (30%); the total mean intensity was (2.75±1.44), it was (2.26±1.33) in males and (2.9±1.45) in females. The effect of some biological factors (sex, weight) of the host on the infection rate has been studied using statistical analysis. It revealed that there is no significant difference between the infected males and females (P˂0.01). Also, larger fish had more infection prevalence than smaller ones. The new species was studied using light and scanning electron microscope.  It is distinct morphologically by the presence of (1) musculated esophageal bulb, (2) extremely short esophagus, (3) the position of gonopore that located very near to acetabulum than the oral sucker, (4) the ovary in the hind body nearer to the posterior extremity than acetabulum, (5) the extension of the uterus (6) the distribution and shape of vitellaria.  SEM revealed the distribution of minute spines on the ventral surface of the worm except on the oral sucker and the inner rim of ventral sucker, the presence of different types of papillae, pits, tegumental folds and ridges.