Purpose of the investigation: The aim of study was to determine the efficacy of radioguided occult lesion localisation (ROLL) for non-palpable invasive breast cancer combined with sentinel lymph node biopsy (SLNB) and to compare the amount of tissue excised by radioguided navigation versus the hook-wire technique. Methods: We injected 45 MBq of radiolabelled technetium intratumourally and 15 MBq subdermally 18 hours before surgery in 21 women with bioptically verified non-palpable breast cancer. We identified by gamma probe non-palpable tumours, which were excised, followed by identification and excision of the sentinel lymph node. We compared our results with a group of 12 women with non-palpable lesions marked by hook-wire localisation. Results: ROLL combined with SLNB was successful in 100%; volume of excised tissue was smaller in the hook-wire group but expressed higher variability in volume than in the ROLL group although the difference was not statistically significant. Conclusion: The method of ROLL combined with SLNB is technically possible and safe, resulting in minimisation of the surgi­cal intervention and a decrease in postoperative morbidity. ROLL was more precise than the hook-wire procedure even though the amount of tissue excised was the same in both groups.