A rapid, sensitive, and facile method for enrichment and separation of trace amounts of gallium was established by using mini column filled Amberlite XAD-4. Gallium(III) as a 4-(2-thiazolylazo) resorcinol (TAR) complex is sorbed on the Amberlite XAD-4 resin and is easily eluted by using 1 M nitric acid in acetone. The determinations of gallium were performed by atomic absorption spectrometry. The influences of the analytical parameters including amounts of reagents, pH of the solutions, and type of eluent were also investigated. The influences of several ions, as interferents, were discussed. The accuracy of the method was demonstrated by recovery on spiked samples. The presented procedure was applied to the determination of gallium in reference standard sediment material (GBW 07309) and water samples with satisfactory results (recovery 95%; relative error 3%; relative standard deviation 10%).