This study reports observed toxicity in a child with acute lymphocytic leukemia who had received vincristine (VCR) with nifedipine and itraconazole. A 5-year-old-child with leukemia developed bilateral cranial nerve palsies, severe peripheral neuropathy involving upper and lower extremities, seizures, hypertension, heart failure, and syndrome of inappropriate antidiuretic hormone secretion after being treated with VCR, nifedipine, and itraconazole. Appropriate management of the above problems including discontinuation of VCR resulted in recovery from neurotoxic manifestations. Concurrent administration of VCR with nifedipine and itraconazole may enhance its neurotoxicity.