Background: Mutations in tumor suppressor genes may facilitate malignant transformation of cells. A TP53 mutation is the most common genetic alteration in breast cancer, and is found in approximately 25 % of breast tumors. A TP53 mutation is shown to be an independent prognostic marker in breast cancer. Recent research indicates that TP53 is mutated in a subtype specific manner, implying diverse roles in tumor development and progression. Objective: The purpose of this study was to examine tumor tissue for mutations in the TP53 gene through direct sequencing. Materials and methods: Tissue samples collected perioperatively from 152 primary breast tumors were analyzed for TP53 point mutations through direct sequencing with 3130xl Genetic Analyzer, Applied Biosystems. Results: Exons 4 and 7 were sequenced and found to harbor four and nine mutations respectively. All mutations found were point mutations with single base substitutions, 11 missense, one nonsense and one silent. Conclusion: All mutations that were found were previously described in the IARC database. The remaining exons must be sequenced to consider the clinical impact of TP53-mutations in the material.