Adult Philadelphia (Ph1) negative acute lymphoblastic leukemia (ALL) is usually treated with conventional chemotherapy regimens. Long-term disease-free survival is often achieved. The rearrangement of immunoglobulin heavy-chain genes has been used to evaluate minimal residual disease. A novel nested-polymerase chain reaction (PCR) approach was used here to study a patient in long-term complete remission (CR) after the BFM regimen. No evidence of tumor cell contamination was found in bone marrow cells collected after 93 months of CR. This finding supports the hypothesis that conventional chemotherapy can induce long-term molecular remission and cure in Ph1 negative ALL.