Purpose <p>The standard 2-day dual-tracer PET protocol provides more information but is time consuming. Thus, this study aimed to validate the feasibility of 1-day ⁶⁸Ga-DOTATATE and ¹⁸F-FDG dual-low-activity PET/MR imaging in patient with neuroendocrine neoplasms (NENs).</p> Procedures <p>Fourteen NENs patients who underwent 1-day ⁶⁸Ga-DOTATATE and ¹⁸F-FDG dual-low-activity PET/MR, and another 14 patients matched with the same primary tumor sites and tumor grades who underwent 2-day ⁶⁸Ga-DOTATATE and ¹⁸F-FDG PET/MR were retrospectively enrolled. Imaging analysis was performed, including lesion detection rate and diagnostic confidence. Additionally, the diagnostic confidence was also assessed based on ⁶⁸Ga-DOTATATE PET, ¹⁸F-FDG PET and PET/MR, respectively.</p> Results <p>The 1-day protocol detected 39 out of 40 lesions in 14 patients, while the 2-day protocol detected 65 out of 66 lesions in 14 patients. No significant differences were observed in lesion detection (all <i>P</i> &gt; 0.05). There was no significant difference in diagnostic confidence between the 1-day protocol and the 2-day protocol for ⁶⁸Ga-DOTATATE PET (median [IQR]: 3[2–3] vs. 3[2–3]), ¹⁸F-FDG PET (1[1–2] vs. 1[1–1]), and PET/MR (4[3–5] vs. 5[4–5]) in all lesions (all <i>P</i> &gt; 0.05).</p> Conclusion <p>The 1-day ⁶⁸Ga-DOTATATE and ¹⁸F-FDG dual-low-activity PET/MR imaging protocol in patients with NENs is feasible and provides equivalent lesion detection and diagnostic confidence compared to the 2-day protocol.</p>