The zebrafish (Danio rerio) was used to investigate protein expression in the liver following arsenic exposure. Several disorders have been linked to arsenic exposure, including cancer, diabetes, and cardiovascular disease. The mechanisms of arsenic toxicity are poorly understood. Prior studies have described altered gene expression, inflammation, and mitogenic signaling in acute or chronic exposure models. A proteomic approach was employed to investigate arsenic-induced alteration in the zebrafish liver proteome following a 7-day exposure to 50 ppb sodium arsenite. Over 740 unique proteins were identified, with fewer than 2% showing differential expression. Molecular pathway analysis software identified lipid metabolism and transport as potential molecular targets. Immunoblots were used to confirm protein expression changes, whereas qPCR was employed to investigate gene expression changes. Overall, 25 proteins were differentially expressed in a gender-specific manner, 11 in males and 14 in females. Of these 25, a single protein, hydroxysteroid dehydrogenase like 2, showed decreased expression in both males and females following arsenic exposure. These findings indicate that protein expression is altered following arsenic exposure. The changes presented here seem to be most prevalent in lipid transport and metabolic pathways, suggesting a potential increase in fibrosis in males and decreased lipid accumulation and uptake in females.