The Southwest Oncology Group (SWOG) studied the response rate and toxicity of piroxantrone (150 mg/m2 q 21 days) in patients with advanced metastatic renal cell carcinoma. Among 32 eligible patients, there were no partial nor complete responses. There were two mixed responses. Significant white cell toxicity, anemia, nausea, and vomiting were observed. Mild or moderate degrees of fever, malaise, and stomatitis occurred. No significant cardiac toxicity was noted. Piroxantrone does not have significant activity as a single agent in advanced renal cell carcinoma.