In this study, anti-inflammatory effects melatonin (Mel) on liver and kidney damage induced by sodium nitrite (NaNO2) used as a food additive were investigated. The study groups were control group (C), NaNO2 group (NaNO2) and melatonin + NaNO2 group (Mel + NaNO2). The first group received dimethyl sulfoxide (DMSO) and the second and third groups received NaNO2 orally for twelve weeks. The third group received melatonin 2 hours before the administration of NaNO2. Administration of NaNO2 (80 mg/kg/day) for 12 weeks orally to rats increased serum aspartate aminotransferase (AST), alanine aminotransferase (ALT) (P<0.001) and urea (P<0.01) levels. Interleukin 1-alpha (IL-1α) (P<0.05) and tumor necrosis factor alpha (TNF-α) (P<0.01, P<0.001 respectively) levels were found to be increased in NaNO2 group in liver and kidney homogenates. It was also determined that IL-6 (P<0.001) levels were increased in kidney tissue. On the other hand, it was also found that there was a decrease at the levels of serum AST (P<0.001), ALT, urea (P<0.05), liver IL-1α, TNF-α (P<0.01), and kidney TNF-α, IL-6 (P<0.05) in group given melatonin (500 μg/kg/day) 2 hours before NaNO₂. In addition, it was observed that there was less liver and kidney damage than NaNO₂ group in the pathological examinations Mel + NaNO₂ applied group. The present data demonstrate that melatonin administration has visible modulatory effects and can eliminate inflammation; moreover, it can prevent the increase in biochemical markers caused by chronic sodium nitrite administration.