Mutations in the TP53 gene are a well-documented strong prognostic factor in breast cancer. A prognostic value of the Arg72Pro polymorphism of the TP53 gene is more contradictory. We assessed TP53 mutations and genotypes of the Arg72Pro polymorphism in a study including 204 Danish women. Patients with mutations in the TP53 gene had a significant reduction in disease-free survival of breast cancer (p < 0.0001). Genotypes of the Arg72Pro polymorphism were neither significantly associated with TP53 mutations nor with disease-free survival (p = 0.4). Among heterozygous patients a reduction in disease-free survival was found for patients with LOH and retention of the Pro allele as compared to patients with LOH and retention of the Arg allele and patients with no LOH (p = 0.05). In conclusion, we find a highly significant prognostic value of TP53 mutations but find a possible prognostic value of the Arg72Pro polymorphism only related to LOH.