Atmospheric lead and its health effects were surveyed in Jakarta, indonesia. Public transportation drivers of small tricycles in downtown Jakarta (exposed group) and farmers who lived in the suburbs of Jakarta (control group) were examined for biomedical effects of lead. Lead concentration in the air along the streets where the drivers work is 3.6 and 1.7 µg/m3with a traffic volume of 5, 148/hour and 1, 284/hour for one side during the day. In the suburbs of Jakarta it was 0.3 µg/m with a traffic volume of 40/hour. The driver group had double the lead concentration both in blood and urine, delta-amlnolevullnic acid (ALA) dehydrase activity decreased by 30%, and higher coproporphyrin excretion compared to the control group on average. The differences were statistically significant. Mean ALA concentration and haematocrit value showed no difference between the groups. An increased absorption of lead and effects of lead at enzyme level are so pronounced that a lead reducing programme of gasoline may be recommended.