Clams (Macoma nasuta) from an unpolluted site in Yaquina Bay, Oregon were exposed in the laboratory for 28 days to 6 field-contaminated sediments (treatments) which varied widely in concentration of 10 organic pollutants. Statistically significant differences were detected between some treatment AFs for DDD (p.p') and benz(a)anthracene, and between some chemicals within treatments (experimentwise alpha = 0.05). Accumulation factors were less than 2 and less variable in highly polluted, organically enriched sediments, but sometimes exceeded 2 in clams exposed to surficial (0-2 cm deep) sediments with low pollutant concentration and low organic carbon content. These results suggest that the AF model may provide reasonable estimates of bioaccumulation potential of hydrophobic neutral organic compounds in organically enriched, polluted sediments.