In recent years intake of n-3 fatty acids with diet became a popular issue due to their importance for human nutrition. Fish oil is the only source of n-3 fatty acids EPA and DHA. It is known that intake of n-3 fatty acids with diet help to reduce cancer and cardiovascular disease risks and LDL cholesterol, decrease joint and muscle inflammations and they could be useful in the prevention and management of AIDS. They have also some positive effects on the glycemic control in patients with diabetes. Supplementing the diet of ladies with n-3 fatty acids improves the quality of pregnancy, decrease the menstrual syndrome and the effects of menopause. They also reduce the risk of depression, and Alzheimer; strength the memory and decrease the complaints of patients with schizophrenia. It is possible to take n-3 fatty acids in diet, or as supplement (capsules or microencapsules). The most common side effect of the consumption of fish oils is the fishy aroma, which may cause the gastrointestinal disturbances and nausea. Besides, some fish contain methyl mercury, and other contaminants, therefore it is mandatory to obtain fish oils and supplements from reliable, and lawful establishments. It was generally recognized as safe to consume 3 g n-3 fatty acids per day.