The knowledge about Se bioavailability from animal food is sparse. This study was therefore initiated in order to evaluate the bioavailability of Se from pork meat in humans. Twelve male volunteers (age 21-30 years) participated in a randomised crossover study with strictly controlled diet containing 170 g pig meat/10 MJ per day and 106 +/- 13 microg Se/d for 3 x 3 weeks. Complete faecal and urinary collections were made during the last week of each period. Bioavailability was evaluated from absorption and retention of Se and changes in plasma Se concentration and blood glutathione peroxidase (GSHPx) activity. The apparent absorption of Se was 94 +/- 2% (100 +/- 13 microg/d). Faecal and urinary excretion were 7 +/- 1 microg/d and 39 +/- 21 microg/d, respectively, resulting in a retention of 61 +/- 24 microg/d. The diet intervention did not affect plasma Se concentration and GSHPx activity. Absorption and retention of Se from pig meat were high suggesting a high availability. However, the availability of pig meat Se for blood Se protein appears to be low.