The Lorestan toad is endemic to Iran and inhabits in the western foothills of the Zagros Mountains, namely Lorestan, Khuzestan, Kohgiluyeh Va Boyer Ahmad and Fars Provinces. In order to investigate the morphological variation in this toad, 15 morphological characters in more than 22 specimens of three regions [Jahangirkhani (lat: 32 46 42 N, long: 48 15 48 E, 454m a.s.l); Tafab (32°46'42N, 48°15'49" E, 461m a.s.l); Paytakht golzar (32°48'18"N, 48°24'6"E; 553m) in the southwest of Iran, were studied. Sexual size dimorphism was computed according to the sexual dimorphism index, where SDI= (average length of larger sex/average length of smaller sex) ±1; the result is arbitrarily defined as positive (+1) if females are larger than males, and negative (-1) if males are the larger sex. The Shapiro-Wilk’s test showed normality of snout-vent length (SVL) (W = 0.947, P = 0.053). So, we used the t-test to compare the SVL between sexes. Patterns of phenetic relationships between local populations was investigated by One-way ANOVA. The SDI was 0.06, indicating an intersexual difference in body length (female-biased SSD), and the SVL differs significantly among females and males according to the t- test (P≤ 0.05). In the intraspecific level, based on morphometric characters, our analysis showed that all populations belonged to a single population, because there was no statistically significant difference between them (ANOVA; P≥ 0.05).