Polychlorinated biphenyl (PCB) levels were determined in 52 samples of adipose tissue removed during surgery from patients residing in a central region of Sardinia who had no previous occupational exposure. The average PCB value of the whole group was 0.72 microgram/g (range 0.11-2.81 micrograms/g); in males the average value (means = 0.97 microgram/g) was significantly higher than in females (means = 0.60 microgram/g). A positive correlation was observed between age and PCB levels in adipose tissue. This analysis could be usefully performed in occupationally exposed subjects so as to better assess the exposure level.