The correlation between peripheral neuropathy and cisplatin (CDDP) was elucidated in 27 patients with primary and metastatic lung cancer, who were treated with Adriamycin 30 mg/m2 day 1, CDDP 80 mg/m2 day 1, and VP-16 70 mg/m2 day 1-5 every 4 weeks. The incidence of peripheral neuropathy was 33% (9 of 27 patients) and it increased to 60% in the patients who received over 320 mg/m2 of CDDP, demonstrating a positive correlation between the incidence of this toxicity and the total dose of CDDP. However, no significant relation was observed between the grade of neuropathy and CDDP. The neuropathy was manifested in the sensory system of the distal extremities and was developed into proximal portions. The peripheral neuropathy with grade 3 was irreversible, resulting in the dose-limiting factor of this regimen.