We report a patient with acute lymphoblastic leukemia who developed severe atypical neuropathy (SAN), distinct from classical vincristine neuropathy, following the use of vincristine and granulocyte colony-stimulating factor (G-CSF). SAN was characterized by acute onset of severe pain, exquisite tenderness on even light touch and profound motor weakness involving predominantly the lower limbs. The upper limbs were spared. Imaging studies and cerebrospinal fluid examination were normal. Electrophysiological studies showed axonal sensorimotor neuropathy. Potentiation of vincristine-induced neuropathy by G-CSF should be considered when formulating protocols using both these agents, and concomitant use of both the agents should be avoided.