Mutations of the p53 gene represent the most common genetic alterations in human cancer. Several reports have focused on p53 polymorphisms as risk factors in lung cancer, in particular at codon 72 of exon 4, encoding either an arginine (Arg72R) or a proline (Pro72P) amino acid. Polymorphisms at codon 72 of the p53 gene were determined using a PCR-RFLP-based method. We analysed the relationship of this polymorphism to patient survival in 121 non-small cell lung cancer (NSCLC) cases. Interestingly, the 72P homozygous NSCLC patients often presented high-grade tumours and had significantly poorer survival rates than patients with R72 homozygotes or heterozygotes. Our results may help clarify discrepancies in the literature concerning the prognostic role of p53 codon 72 variants.