We have studied three different lavage procedures (100, 200 and 300 ml) in patients with pulmonary sarcoidosis (stage I). The effect of bronchoalveolar lavage (BAL) on cell yield, lavage fluid recovery, dwelling time, lavage-induced arterial oxygen desaturation and occurrence of side effects was analyzed. The patients did not differ significantly in prelavage lung function and blood gas parameters. The lowest BAL return was seen in the 300-ml lavage procedure (49.5%), while the medium yielded over 70%. The lowest cell yield was seen in the BAL 100 group (10.4 X 10(6)); the highest in the BAL 300 (19.4 X 10(6)), but the latter did not differ significantly from BAL 200 (18.4 X 10(6)). Dwelling time of the fluid differed only slightly between the small and middle volume lavage (average 3.2 vs. 3.9 min p less than 0.01), but was significantly lower from the average dwelling time in the BAL 300 group (9.8 min, p less than 0.001). Arterial oxygen desaturation was lowest in the BAL 100 and most pronounced in the large-volume lavage. Side effects were seen in all but 1 patient undergoing BAL 300. Cough was the most often reported side effect (9 patients); fever was observed in 6 patients, dyspnea in 4 (all undergoing large-volume lavage). Considering our results we do not think that it is justifiable to increase the volume of instilled fluid above 200 ml, because this may lead to serious side effects without increasing benefits. Using lower than 200 ml volumes decrease diagnostic yield although the risk of developing side effects is much lower.