Abstract Objectives We aimed to determine the radioguided occult lesion localization (ROLL) reliability in the reoperation of patients with differentiated thyroid cancer (DTC) and persistent or recurrent non‐palpable loco‐regional disease who underwent surgery at the Instituto Nacional de Cancerología between 2012 and 2021. Design Observational retrospective cohort study. Participants We included data from patients with DTC that underwent resection with ROLL. Main Outcome Measures Reliability analysed as percentage of patients with complete resection of tumour lesion using ROLL, disease‐free survival, second loco‐regional relapse, adequate resectability and complications. Results Two hundred and four cases were obtained. Pathological examination revealed papillary thyroid carcinoma in 202 patients, and follicular thyroid carcinoma in 2. Reliability was 96.57% in patients who underwent ROLL. When wide resection was performed—at surgeon's discretion—the reliability increased to 97.5%. Conclusions The high reliability obtained suggests that ROLL was effective to localize non‐palpable relapsing lesions. To our knowledge, this is the largest sample size published on this topic to date.