In this research, the combined and separate effects of temperature and aluminum on growth, survival, yolk sac absorption and bone anomaly in newly hatched larvae of Nile Tilapia ( Oreochromis niloticus ) were investigated. Four hundred twenty yolk sac larvae with average weight of 0.0064-0.0071 g were divided into 3 groups, each had four treatment. The groups were: optimum temperature (26.5-27.5?c), high temperature (33.5-34.5?c), and low temperature (20.5-21.5?c) and the treatments contain: without aluminum, 10%, 20% and 30% of LC50 aluminum. During the experimental period, survival rate, growth performance and time of yolk sac absorption were examined daily by using 5 larvae for each treatment. At the end of the experiment, larvae were sampled for skeletal tissue staining as well as aluminum, calcium, phosphorus, magnesium, zinc, copper and phosphorus content of whole-body. Result were showed that the increase temperature has a significant effects on larvae growth rate (P 0.05) but has not a significant effect on larvae survival (P 0.05). Increase in aluminum concentration reduced growth and survival. Such a situation can also be seen in combined treatments (P 0.05). Based on the results, the temperature accelerated the absorption of yolk sac, but aluminum in high temperature treatments delayed this phenomenon. Temperature and aluminum did not have a significant effect on heart rate of larvae separatly and in combination form (P 0.05). Temperature also did not effect on the incidence of malformation in the larvae. However, by increasing the concentration of aluminum, anomalies (lordosis, kyphosis, fusion in the neural spine and etc) increased to 20% in larvae. Also, combined aluminum and temperature increased the anomalies in the larvae. Increase temperature led to increase level of calcium and aluminum although the absorption of copper and magnesium was reduced at high temperature (P 0.05). In addition, the lowest amount of phosphorus was observed at low temperatures (P 0.05). With increase in aluminum concentration, the absorption of calcium, magnesium, phosphorus and zinc was reduced, but the absorption of aluminum increased with increasing their concentrations in water. The combined effect of aluminum and temperature resulted in a further reduction of calcium content and an increase in aluminum uptake (P 0.05), but no significant difference was observed in other elements (P 0.05). In conclusion, the results showed that temperature and aluminum may alter larval growth performance and yolk sacs absorption. Moreover, changes in the level of aluminum and temperature led to an impairment in larval development and increased skeletal anomalies and changes in the absorption of calcium, magnesium, phosphorus and zinc in the larvae of Nile tilapia. Key word : Yolk sac absorption, Larvae evolution, Skeletal anomalies, Aluminum, Temperature, Oreochromis niloticu s