Medulloblastoma is a highly cellular malignant embryonal neoplasm, being the most common malignant pediatric brain tumor, accounting for 20-25 % of pediatric central nervous system tumors. To investigate the effect of the TP53 Arg72Pro single-nucleotide polymorphism (SNP) on clinicopathological and phenotypic parameters, we performed a case-controlled study of 122 patients and 122 healthy controls from Brazil. No significant associations were found between the TP53 Arg72Pro genotypes and the clinicopathological parameters studied. Compared with Arg/Arg, which is the most common genotype in the study population, both the Arg/Pro and Pro/Pro genotypes did not influence the medulloblastoma development risk [odds ratio (OR) = 1.36 and P = 0.339 for the Arg/Pro genotype; OR = 1.50 and P = 0.389 for the Pro/Pro genotype]. With regard to prognosis, disease-free survival was not significantly different among the TP53 Arg72Pro SNP genotypes (P > 0.05), but the less frequent genotype (Pro/Pro) was associated with shorter overall survival of medulloblastoma patients (P = 0.021). These data suggest that, although there is no association between the TP53 Arg72Pro SNP and medulloblastoma risk, the Pro/Pro genotype is associated with shorter overall survival of patients submitted to adjuvant therapy. Nevertheless, due to the interethnic composition of the Brazilian population, future studies on larger populations from other parts of the world are essential for a definitive conclusion on the function of the TP53 Arg72Pro SNP.