Abstract: The present study aimed to evaluate the effect of leptin addition (0, 10, 20 and 30 ng mL-1) to maturation media on in vitro maturation (IVM) and fertilization (IVF) of dromedary camel oocytes. Ovaries were collected from slaughtered animals, oocytes were collected by slicing technique and matured in TCM-199 medium with different leptin levels in CO2 incubator (5% CO2) at 38.5°C and high humidity for 42 h. After maturation, oocytes were categorized as Germinal Vesicle (GV), Germinal Vesicle Breakdown (GVBD), metaphase-I (MI), metaphase-II (MII) and degenerated oocytes. Epididymal spermatozoa were recovered from camel testes immediately after slaughter. In vitro fertilization was carried out for oocytes matured in TCM-199 with 10% FDCS plus 20 μg mL-1 of leptin. Spermatozoa and oocytes were co-incubated at 38.5°C in a moisture atmosphere of 5% CO2 in air for 20-24 h. The cleaved oocytes were examined after five days of culture for cleavage stages (2, 4 and 8-16 cell, morula and blastocyst stages). Results revealed that supplementation of leptin (20 mg mL-1) showed (p<0.05) the highest percentage of oocytes at MII (58.8%) and the lowest percentages of those at GV (7.8%), GVBD (9.8%), MI (10.8%) and degenerated oocytes (12.7%) as compared to control medium (40.0, 10.9, 11.8, 14.5 and 22.7%, respectively) and other levels of leptin. Supplementation of leptin, matured with 20 ng mL-1 leptin increased fertilization rate (27 vs. 25.3%) and blastocyst rate (3.6 vs. 1.4%) as compared to the control medium. In conclusion, supplementation of leptin to maturation medium (TCM-199) at a level 20 ng mL-1 increased in vitro nuclear maturation rate of immature oocytes and their fertilization rate and blastocyst production.