Purpose: Phase II studies were conducted toevaluate the safety and efficacy of the interferon inducerPoly ICLC at low doses in advanced renal cancer and relapsedor refractory lymphoma. Patients and methods:Twenty-nine patients with advanced renal carcinoma and elevenpatients with lymphoma were treated with poly ICLC. Patientsreceived 0.25 mg/m² of poly ICLC intravenouslytwice weekly three days apart until progression orunacceptable toxicity. Results: There were noobjective responses. Six patients with renal carcinoma hadstable disease as best response with one patient receiving 62weeks of therapy. Toxicity included grade 3 anemia in 8patients and grade 4 anemia in one patient. All patients wereanemic prior to entry with a median grade 2 anemia atbaseline. Grade 4 neutropenia, thrombocytopenia and injectionsite pain occurred in one patient each. Grade 3 fever, chillsor fatigue occurred in four, three, and three patientsrespectively. Any grade fever occurred in 10 patients(25.6%) and any grade chills occurred in 9 patients(23.1%). Conclusion: Poly ICLC at this doseand schedule is well tolerated in both patient populations andis inactive in renal carcinoma.