ABSTRACT The purpose of the current study was to examine the effects of different feeds/nutrients and temperature on the gonadal development of Clarias gariepinus. The gonadosomatic index (GSI) and blood parameters including red blood cell count (RBCs), white blood cell count (WBCs), hemoglobin (Hgb) level, hematocrit (HCT), platelets (PLT) and mean corpuscular volume (MCV) were investigated. Four types of fish feed of 36% protein content [D1(fish meal), D2 (soybean meal), D3 (peameal) and D4 (commercial tilapia feed)] and 3 different levels of temperature (T1(24℃), T2(28℃) and T3(32℃) were tried in this study for a duration of 4 months. The mean values were as follows: female GSI (14.68 ± 4.86), male GSI (0.70 ± 0.32), RBCs x 106(2.45± 0.64), WBCs x 103(9.28 ± 2.34), Hgb (12.42± 2.21g/dl), HCT (29.06 ± 3.54%), PLT (90.75 ± 9.18/mm3), and MCV (118.08 ± 10.3 g/l). Fish meal diet revealed the most significant (p<0.05) increase in weight gain, female GSI, and also exerted significant increases on most of the blood parameters. This study revealed that animal-based protein diet and temperature around 28℃ were the critical requirements for the physiological performance and relative gonadal weight of C. gariepinus. GSI and blood parameters were useful indicators of stress exerted by nutrition and temperature on fish, and their study is critical for fish health and mass production of viable seeds for aquaculture enterprise.