The structures of three isomeric 1,2,3,4-tetrahydroxytetrahydronaphthalene metabolites of naphthalene have been confirmed by synthesis. Six isometric 1,2,3,4-tetrahydroxy-1,2,3,4-tetrahydronaphthalene structures occurring in for dl-pairs and two mesoforms have been synthesized. Five were synthesized by the action of osmium tetroxide on the cis- and trans-1,2-dihydrodiols and cis- and trans-1,4-dihydrodiols. The sixth isomeric tetrahydrotetrol was synthesized by hydrolysis of trans-1,2-dihydroxy-syn-3,4-epoxy-1,2,3,4-tetrahydronaphthalene (the syn-dihydrodiolepoxide of naphthalene). By comparing the gas-chromatographic and mass-spectrometric properties of the synthetic and urinary tetrahydrotetrols, two of the urinary metabolites were identified as 1 beta, 2 alpha, 3 alpha, 4 beta- and structure of the third tetrahydrotetrol metabolite, 1 beta, 2 alpha, 3 beta, 4 alpha-tetrahydroxy-1,2,3,4-tetrahydronaphthalene, identified in earlier studies, was confirmed.