A method has been developed for isolating alveolar type II cells by digesting lung tissue with elastase and "panning" the resultant cell suspension on plates coated with IgG. This method provides both high yield and purity of type II cells. In 50 experiments with rats, we obtained 35 +/- 11 X 10(6) cells/rat, 89 +/- 4% of which were type II cells (mean +/- SD). Type II cells isolated by "panning" adhered more rapidly and completely in tissue culture than did cells isolated by centrifugation over discontinuous density gradients of metrizamide. The "panning" method is superior to other methods for isolating type II cells in that it provides a population of type II cells of both high yield and high purity. The method is fast, reproducible, and easily adaptable to isolating type II cells from species other than rats.