Enzymuria and beta 2-microglobulinuria are sensitive markers of injury to renal tubular cells. We evaluated these markers in 41 patients with advanced malignant lymphoma who received gallium nitrate administered as a continuous infusion during a recent phase I-II study. In contrast to our findings with cisplatin, we observed no significant increase in enzyme excretion or beta 2-microglobulinuria in these patients even after long-term treatment. Our results indicate that gallium nitrate administered by infusion does not produce cumulative renal tubular toxicity.