This study deals with the metabolism of gallium arsenide (GaAs). GaAs was shown to be soluble in various media. Since this compound could dissolve in aqueous solvents, in vivo dissolution was investigated. Hamsters were used to study the dissolution and subsequent pharmacokinetics of any liberated arsenic species. The fecal and urinary excretion data following oral and intraperitoneal administration showed that GaAs, when administered orally, is mostly excreted in the feces but poorly in the urine, and that the compound, when administered intraperitoneally, is poorly excreted in both the feces and urine. Analysis of tissues for arsenic levels yielded concentrations in the ppb range, which further verified this fact. Most interesting was the fact that dimethylarsinic acid (DMAA) and methylarsonic acid (MAA) along with inorganic arsenic were found in the urine and tissues. GaAs was shown to dissolve in vivo and the released arsenic species were metabolized as other inorganic arsenics were found in the urine and tissues. GaAs was shown to dissolve in vivo and the released arsenic species were metabolized as other inorganic arsenic containing compounds. The low solubility and poor oral absorption may make this compound less toxic than other inorganic arsenic compounds.