The metabolic profile of carbinoxamine, 2-[(4-chlorophenyl)-2-pyridinyi-methoxy] N, N-dimethylethanamine, was determined in rat urine. Urinary extracts obtained with or without enzyme hydrolysis were derivatized with MSTFA/TMSCI (N-methyl-N-trimethylsilyl trifluoroacetamide/Trimethylchlorosilane) and analyzed by GC/MSD. In rat urine, which obtained after oral treatment with carbinoxamine maleate, chlorobenzolyl pyridine, (4-chlorophenyl)-2-pyridinyl methanol : carbinol, 2-[(4-chlorophenyl)-2-pyridinylmethoxy]-N-methylethanamine : norcarbinoxamine, 2-[(4-chlorophenyl)2-pyridinylmethoxy]ethanamine : bis-norcarbinoxamine and parent carbinoxamine were detected in free form. Norcarbinoxamine and bisnorcarbinoxamine were also detected in conjugated form(acetylation). These data suggest that in the rat, hydroxylation of either the benzyl or pyridinyl ring can occur during carbinoxamine elimination. O-demethylation and subsequent conjugation represents the primary pathway of carbinoxamine elimination in the rat.