the composition of fish oil agrees with the value generally reported,described in the introduction chapter. As previously stated, fish oil differs considerable from other oils, namely due to its content of PUFA. However, due to its high content, these oils are very prone to oxidation. In fact,results from the present study indicate that this oil presents very important subject. considering the use for biodiesel production,raw material oxidation is also detrimental, as it increases the acid value and reduces the quality of the oil. The results show that a great care is required during the storage of such oil to prevent oxidation