Surface sediments collected from 19 stations along Visakhapatnam harbour were analysed for organic carbon (OC), delta sup(13)C sub(oc), total lipids (TL), total hydrocarbon (THC), n-alkane concentration and composition. OC, delta sup(13)C sub(oc), TL and THC ranged from 0.6 percent to 7.6 percent, -29.3 to -23.8 ppt, 300 to 14,948 mu g g sup(-1) dw, and 0.2 to 2,277 mu g g sup(-1) dw, respectively. Predominance of even carbon numbers n-alkanes C12–C21 with carbon preference index (CPI) of less than 1 suggests major microbial influence. Fair abundance of odd carbon number n-alkanes in the range of C sub(15)–C sub(22) and C sub(23)–C sub(33) indicates some input from phytoplankton and terrestrial sources, respectively. Petrogenic input was evident from the presence of hopanes and steranes. The data suggest that organic matter (OM) sources varied spatially and were mostly derived from mixed source.