Pseudomonas sp. strain NGK1, a soil bacterium isolated by naphthalene enrichment from biological waste effluent treatment, capable of utilizing 2-methylnaphthalene as sole source of carbon and energy. To deduce the pathway for biodegradation of 2-methylnaphthalene, metabolites were isolated from the spent medium and identified by thin-layer chromatography and high-performance liquid chromatography. The characterization of purified metabolites, oxygen uptake studies, and enzyme activities revealed that the strain degrades 2-methylnaphthalene through more than one pathway. The growth of the bacterium, utilization of 2-methylnaphthalene, and 4-methylsalicylate accumulation by Pseudomonas sp. strain NGK1 were studied at various incubation periods.