This research was conducted to determine the usefulness of reported symptoms for the diagnosis of lead poisoning for workers exposed to lead. A group of 147 male lead smelting workers were given special physical examinations from June to September of 1989. The examinations included the reporting of ailments(symptoms) by the workers, as well as analyses of their blood lead concentrations and urinary coproporphyrine and delta-aminolevulinic acid concentrations. the associations were analyzed between the bilogical exposure indices and the symptoms described by the workers. The results were as follows: 1. The only symptoms which were described more frequently by the lead workers compared to the control group were paresthesia of the extremities, myalgia, arthralgia, and insomnia. The frequency of other symptoms described were actually lower for the lead-exposed workers. 2. For those workers whose blood lead concentrations were above 60 microgram/dl, only the increase in the frequencies of arthralgia and paresthesia of the xtremities were statistically significant, compared to those workers whose blood lead concentrations were below 60 microgram/dl. Also, arthralgia was the only symptom which increased in frequency in workers whose ruinary coproporphyrine concentrations were above 100 microgram/l; however, this increase was not statistically significant by urinary delta-aminolevulinic acid levels.