Neoplastic tissues from 28 adults with malignant lymphoma were examined for glucocorticoid receptors and in-vitro sensitivity to glucocorticoids. The patients were then treated with dexamethasone for 5-14 days. 13 patients achieved at least a partial remission, and 15 had no significant tumour response. Lymphoma cells from patients who responded had more glucocorticoid-receptor sites per cell and greater in-vitro sensitivity as measured by glucocorticoid inhibition of incorporation of leucine and uridine than did tumour cells from non-responders. Study of tumour glucocorticoid receptors and glucocorticoid sensitivity in vitro may allow selection of those patients with lymphoma who should receive glucocorticoids as part of combination chemotherapy.