BACKGROUND To assess the relation between occupational lead exposure and elevated blood pressure with consideration of a possible confounding effect by noise exposure. METHODS Some 112 male and 110 female workers at two lead battery manufacturing factories were recruited for this 1992 study in Taiwan. Study participants received regular physical examinations, including standard measurement of blood pressure, body height/weight. Current occupational exposures to lead and noise were measured by a personal sampling scheme and instruments, and included individual ambient lead/noise exposure and blood lead level. RESULTS Among the 222 battery-factory workers, the average blood lead level was 56.9 +/- 25.5 micrograms/dl (mean +/- standard deviation), the average concentration of ambient lead exposure was 0.190 +/- 0.331 mg/m3, average noise exposure was 85.9 +/- 5.7 dBA, average systolic blood pressure was 125.2 +/- 14.9 mmHg, average diastolic pressure was 80.2 +/- 10.9 mmHg, and average mean arterial pressure was 95.2 +/- 11.1 mmHg. After considering all possible confounding variables, multivariate regression analyses demonstrated that current blood lead level was not a significant predictor for both systolic and diastolic blood pressures in either sex. In the final model, body mass index and years of working in the factory were the only two factors significantly associated with a change in blood pressure. No evidence of an effect of ambient lead exposure or noise exposure on blood pressure were found. CONCLUSIONS The present study suggests that short-term lead exposure, either ambient lead exposure or blood lead level, was not related to blood pressure change among workers who had been exposed at work to occupational lead. These results add to the body of evidence indicating that blood lead exposure does not adversely affect blood pressure.