Mercury is considered to be one of the most harmful metals. Studies of the so-called normal mercury content in human internal organs, blood, and urine can be useful for assessment of the level of environmental exposure and also for legal and medical expert opinions. The examination encompassed 75 autopsies of inhabitants of southern Poland (50 male and 25 female) investigated at the Institute of Forensic Research in Kraków, Poland, between the end of 1998 and the beginning of 2001. Samples of internal organs were homogenized and digested with nitric and sulfuric acids. Determination of total mercury was performed by the use of cold vapor atomic absorption spectrometry. The following results (range and mean, in ng/g wet weight) were obtained: brain (n = 49) 0-14.2, 2.3 +/- 1.9; liver (n = 69) 2.6-55.0, 15.5 +/- 9.5; kidney (n = 63) 3.2-170, 35.9 +/- 31.7; heart (n = 4) 1.2-2.8, 2.2 +/- 0.75; spleen (n = 17) 2.4-9.6, 4.0 +/- 1.8; lung (n = 22) 1.8-9.1, 3.3 +/- 1.8; stomach (n = 48) 0-4.5, 2.0 +/- 1.0; small intestine (n = 32) 0-14.2, 2.8 +/- 2.7; large intestine (n = 13) 0 - 23.9, 5.2 +/- 7.2; blood (n = 35) 0 6.5, 1.6 +/- 1.2; urine (n = 14) 0 2.6, below detection limit. The above mentioned levels of mercury are similar to those reported by other Polish authors, but are lower than those determined in normal Korean and Japanese organs.