Bone marrow suppression (anemia, neutropenia, thrombocytopenia) is the most commonly occurring side effect of chlorambucil.
Serious side effects included severe myelosuppression (suppressed activity of bone marrow, which is involved in formation of various blood cells found in 98% of patients), disorder of the respiratory system, tumor lysis syndrome, Type III hypersensitivity, venous occlusion, and death.