The hypothesis that the availability of food increases the rate of depuration of DST in mussels (Mytilus edulis) was tested in a laboratory experiment. Mussels naturally containing DST (mean 500 µg OA kg-1 mussel meat) were collected from a mussel farm located on the Swedish west coast during a bloom event. Individual mussels were placed in filtered seawater and given daily rations of a mixture of non-toxic algae as follows: starvation (no food), 0.5% and 1.5% of dry weight body mass day-1. The contents of okadaic acid (OA) and dinophysistoxin-1 (DTX-1) were analyzed using HPLC after 1, 2, 4, 8, 16 and 32 days. Also, the amount of accumulated faeces, total flesh weight and digestive gland weight were measured at the end of each treatment. OA was the major toxin found in all mussels and low amounts of DTX-1 (<10%) were found only in a few specimens. The levels of OA decreased in all treatments with time. In contrast to predictions, levels of toxins were significantly lower in the starvation treatment compared to both food treatments after 32 days. The loss of toxins in the starvation treatment were correlated with a significant loss in the weight of the digestive gland between 16 and 32 days. Only the starvation treatment reached levels of OA below the limit for marketing of mussels at the end of the experiment. We conclude that the mechanisms for depuration of OA from mussels are not associated with turn-over of nutrients and fecal production. In management of toxic mussels, depuration is not likely to be enhanced by adding food to mussels.