Lead levels were determined in the blood, scalp hair and fingernails of 38, all male auto-mechanics (aged 18-45 years) from Abeokuta, South-western Nigeria. The subjects were classified into four sub-groups based on the period of exposure namely: 1-5, 6-10, 11-15, and >16 years. Thirty-two occupationally unexposed subjects (mainly office workers) served as the control. The weight, height and body mass indexes of all subjects were noted, in addition to other information obtained through structured questionnaire. The mean values of blood lead (BPb), hair lead (HPb) and fingernail lead (NPb) of the occupationally exposed subjects (n=38) were 48.50 +/- 9.08 microg/dL, 17.75 +/- 5.16 microg/g, and 5.92 +/- 3.30 microg/g respectively, while the corresponding mean values for these parameters in the control subjects (n = 32) were 33.(,5 +/- 10.09 microg/dL, 14.30 +/- 5.90 microg/g and 5.31 +/- 2.77 microg/g respectively. The differences in BPb and HPb levels of the two groups were statistically significant (P <0.05 and P <0.01 respectively), while that of NPb was not significant. The levels of lead in the biological samples appeared to have no relationship with the number of years on the job. From these results, it was obvious that the higher levels of lead in the biological samples of test subjects, compared with those of the controls were from environmental sources.