Determining the concentration of garlic extract addition in commercial feeds that are effective for increasing the body's resistance and survival of nilem fish to the attack of Aeromonas hydrophila bacteria. This study was carried out at the Aquatic animal physiology laboratory of building 2 and the biotechnology laboratory, faculty of fisheries and marine sciences, Universitas Padjadjaran, between November and December 2021. This study used the Complete Randomized Design (CRD) method with five treatments and three tests. The treatment used is the addition of garlic extract to commercial feed at doses: 0 g / kg of feed (A), 10 g / kg of feed (B), 20 g / kg of feed (C), 30 g / kg of feed (D), and 40 g / kg of feed (E). The treatment period is carried out for 21 days. Furthermore, nilem fish were tested with Aeromonas hydrophila bacteria with a density of 108 CFU / ml by intramuscular injection. The results showed that the addition of garlic extract to the feed did not produce a noticeable influence on the survival value of fish. However, the administration of garlic extract into the feed of 20 g / kg affects the health of the fish body in the form of a white blood cell count of 12800 cells / mm3.