Alternaria toxins are emerging mycotoxins that gained considerable interest with increasing evidence of their existence and toxicological properties. There is limited research and insufficient data about their in vivo hazardous effects. We designed this study to evaluate histopathological and genotoxic in vivo impacts of alternariol (AOH) on the parotid gland as well as to assess the competency of gallic acid (GA) in reversing these effects. Forty healthy adult male Wister rats were utilized and assigned equally on control, GA, alternariol and AOH+ gallic treated groups. Parotid gland samples from experimental groups were collected and then examined for histopathological, ultrastructural and immunohistochemical examination for 4-hydroxynonenal “4-HNE as lipid peroxidation marker” as well as Comet assay for DNA damage. Additionally, parotid tissue homogenates were tested for catalase “CAT”, superoxide dismutase “SOD” and malondialdehyde “MDA” levels. Our data proved that alternariol produced various histopathological and ultrastructural alterations of parotid acini as well as significant DNA damage, significant reduction of CAT and SOD enzymatic activity and significant boosting of 4-HNE immunohistochemical expression and MDA levels as compared to control group. On the other hand, gallic acid administration almost restored histological and ultrastructural parotid architecture, 4-HNE immune-expression and biochemical levels. Ultimately, we demonstrated alternariol-induced histopathological and genotoxic alterations on parotid gland as well as the competency of gallic acid in reversing these effects.