Abstract The ability of cells recovered from lung lavages to phagocytose liposomes has been investigated. Inulin ( 14C-labelled), entrapped in multilamellar immunoglobulin-G coated liposomes with 3H-labelled cholesterol as the lipid phase marker, was fed to the recovered cells. Fifteen patients with diffuse interstitial pulmonary disease (DIPD), prior to steroid treatment, and eight normal controls were lavaged for the study. Uptake was found for both groups and it was concluded that the liposomes enter the cells predominantly via endocytosis. Follow-up lavage, three months after the initial lavage, was repeated on three patients receiving 60 mg prednisone per day. A decrease in the uptake of liposomes was observed after steroid treatment.