Aluminum (Al), which has wide usage areas, is released into aquatic environments by natural processes and anthropogenic sources including coal strip mining activities, water treatment facilities using aluminum hydroxide (AH) as a coagulant for suspended solid particles, industrial wastes and acid rainfall. With the acidification of surface waters, Al is able to pass into organisms and provoke toxicity in fish. On the other hand, several boron compounds such as borax (BX) and boric acid (BA) are of great interest as natural sources of protective agents due to their key biological functions in animals and humans. In this study, the toxicity potential of AH at high doses were investigated using multiple marker applications including hematological index, oxidative stress parameters, proinflammatory cytokine expressions, DNA damage as well as apoptosis markers in blood and liver tissues of rainbow trout. Moreover the effects of borax in alone and AH-combined applications were also assessed. Our findings revealed that the exposure to AH led to alterations in hematological indices, increased the genotoxic and oxidative damage as well as apoptosis. Again, AH induced significant changes in levels of pro-inflammatory cytokines. However, these effects were modulated by the supplementation of BX. Based on the findings of our study, borax appeared to be promising protective agent to alleviate aluminum-associated hemato- and hepatotoxicity in fish.