A phase II trial of combination chemotherapy with mitoxantrone, cisplatin, and methyl-glyoxal bix-guanylhydrazone (MGBG) was conducted in 32 patients with unfavorable histology malignant lymphoma. All patients had relapsed after only one prior chemotherapy regimen (CHOP--56%; mBACOD--28%). There were three complete and eight partial responses (overall response rate--34%) among 32 eligible patients. The median duration of remission was 6.0 months. Severe granulocytopenia was common, with 19/32 patients (63%) suffering life-threatening, and 1/32 (3%) suffering fatal, granulocytopenia. We conclude that mitoxantrone-cisplatin-MGBG has modest activity as salvage treatment in malignant lymphoma patients, but produces severe toxicity.