Four subjects working in sharpening and grinding operations of hard metal tools were examined. Only 1 worker, a 37-year-old female exposed for 7 years to hard metal dusts, developed hard metal pneumoconiosis, which rapidly progressed to death. Cytology of the bronchoalveolar lavage (BAL) showed a high number of eosinophils, more than 30% of the cell population. Biopsy of the lung revealed interstitial fibrosis with hyperplasia of the pneumocytes of the second type and inflammatory cellular infiltration of the interstitium. High tungsten (W) and tantalum concentrations were determined in the admission BAL and in the biopsy 4 months later by neutron activation analysis while cobalt (Co) levels were near to normal values. The content of Co and W in blood and urine and particularly in pubic hair and toe nails of the patients was significantly higher than the normal values. This suggests that these biological specimens could be used as indicators of chronic exposure to hard metal dusts.