Abstract The concentrations of various organic pollutants (PCBs, phthalate esters (PAEs), hexachlorobenzene (HCB), pentachlorophenol (PCP), polycyclic aromatic hydrocarbons (PAHs), and chlorinated hydrocarbon pesticides (CHPs)) were determined in samples of water and sediment from various sites in the Nueces Estuary, Texas. In sediment, the relative concentrations were ∑PAEs ⪢ PCB > ∑CHPs > PCP > HCB; the relative concentrations in water were ∑PAEs > PCP > PCB > ∑CHPs > HCB. One site in the estuary was highest in regard to most of the pollutants. The results of this study are compared to values reported for other sites. This study is part of a larger effort to evaluate and characterize environmental pollution and to assess the biological effects of marine pollutants. It will also serve as a basis for intercomparison with other areas and for future monitoring.