The aim of this study was: (a) to estimate the concentration of selenium in plasma of 136 residents (59 men and 77 women) of the Gdansk region, northern Poland, aged 19-70; and (b) to compare the obtained results with data corresponding to healtly populations living in different European countries. Selenium in plasma was determined by atomic absorption spectrometry using the hydride generation method. The mean selenium concentration in plasma of the investigated persons was: 72.3 +/- 14.1 mug/l, in men 75.9 +/- 12.8 mug/l, in women 69.5 +/- 14.7 mug/l. No age-dependent differences in plasma selenium were found in the investigated population. In 22% of the investigated persons the selenium level in plasma was lower than 60 mug/l. The obtained results indicate that a significant part of this population is deficient in selenium and should be supplemented with this element.