BACKGROUND: We conducted a study on radiation exposure in patients with gastroenteropancreatic neuroendocrine neoplasms (GEP-NENs) treated with [Lu]Lu-DOTA-TATE in China for the first time, aiming to provide guidance and reference for radiation protection in this regard. A total of 30 GEP-NENs patients who received [Lu]Lu-DOTA-TATE therapy were recruited in the study. We measured the external dose rate (EDR) values of each patient during the injection and 0-6 h post-administration period, as well as the radiation dose (RD) values to healthcare nurses and the surrounding environment. We performed a double exponential curve fitting and estimated the RD to the public from patients discharged at different times after [Lu]Lu-DOTA-TATE therapy. RESULTS: Among the 30 patients, 27 patients completed 4 cycles of [Lu]Lu-DOTA-TATE treatments, the estimated RD to the public indicated that for adult family members, children above 10 years old, children aged 3-10 and coworkers of the patients, patients could begin daily contact at least 24 h, 48 h, 144 h and 192 h after injection to ensure that the total RD values after four treatments not exceed the limit. During the hospitalization of patients receiving [Lu]Lu-DOTA-TATE, the cumulative dose received by the administering nurses and to the ward environment were both well below the national RD limits. CONCLUSIONS: This study conducted a fitting analysis of the decay pattern of EDR values in GEP-NENs patients undergoing [Lu]Lu-DOTA-TATE therapy, in order to establish guidelines for patient discharge timing and provide recommendations for radiation protection for the general public after patient discharge. Trial registration A Study Comparing Treatment With Lutetium[177Lu] Oxodotreotide Injection to Octreotide LAR in Patients With GEP-NETs, NCT05459844. https://clinicaltrials.gov/study/NCT05459844?cond=NCT05459844&rank=1 . Registered 5 July 2022.