For the management of non-palpable breast cancer, accurate pre-operative localisation is essential to achieve complete resection with optimal cosmetic results. Radioguided occult lesions localisation (ROLL) uses the radiotracer, injected intra-tumourally for sentinel lymph node identification to guide surgical excision of the primary tumour. In a multicentre randomised controlled trial, we determined if ROLL is superior to the standard of care (i.e. wire-guided localisation, WGL) for preoperative tumour localisation. Women (>18 years.) with histologically proven non-palpable breast cancer and eligible for breast conserving treatment with sentinel node procedure were randomised to ROLL or WGL. Patients allocated to ROLL received an intra-tumoural dose of 120 Mbq technetium-99 m nanocolloid. The tumour was surgically removed, guided by gamma probe detection. In the WGL group, ultrasound- or mammography-guided insertion of a hooked wire provided surgical guidance for excision of the primary tumour. Primary outcome measures were the proportion of complete tumour excisions (i.e. with negative margins), the proportion of patients requiring re-excision and the volume of tissue removed. Data were analysed according to intention-to-treat principle. This study is registered at ClinincalTrials.gov, number NCT00539474. In total, 314 patients with 316 invasive breast cancers were enrolled. Complete tumour removal with negative margins was achieved in 140/162 (86 %) patients in the ROLL group versus 134/152 (88 %) patients in the WGL group (P = 0.644). Re-excision was required in 19/162 (12 %) patients in the ROLL group versus 15/152 (10 %) (P = 0.587) in the WGL group. Specimen volumes in the ROLL arm were significantly larger than those in the WGL arm (71 vs. 64 cm(3), P = 0.017). No significant differences were seen in the duration and difficulty of the radiological and surgical procedures, the success rate of the sentinel node procedure, and cosmetic outcomes. In this first multicentre randomised controlled comparison of ROLL versus WGL in patients with histologically proven breast cancer, ROLL is comparable to WGL in terms of complete tumour excision and re-excision rates. ROLL, however, leads to excision of larger tissue volumes. Therefore, ROLL cannot replace WGL as the standard of care.