To evaluate the reporting quality of recent randomised controlled trials (RCTs) of acupuncture for low back pain (LBP) and investigate associated factors.A systematic review was conducted to identify and evaluate the reporting quality of RCTs of acupuncture for LBP reported after 2020. The Consolidated Standards of Reporting Trials (CONSORT), STandards for Reporting Interventions in Clinical Trials of Acupuncture (STRICTA) and CONSORT-Outcomes statements were used to evaluate the reporting quality of the included studies. Regression analyses were performed on pre-specified study characteristics to explore factors associated with the reporting quality.Cochrane Library, PubMed, Web of Science, Embase, China National Knowledge Infrastructure (CNKI), Wan Fang, VIP Database and Chinese Biomedical Literature Database were systematically searched from January 2021 to January 2025.Only RCTs enrolling patients with LBP diagnosed according to the criteria of the North American Spine Society or other recognised clinical guidelines were included. The eligible interventions comprised manual acupuncture, electroacupuncture and other acupuncture-related therapies. Publication language was restricted to English and Chinese.Literature screening, data extraction and reporting quality assessment were independently conducted by two reviewers with professional training. Any discrepancies were resolved by a third reviewer.Fifty-seven RCTs were ultimately included, with a median overall quality score of 32 (range, 17-54). The CONSORT-based median quality score (QS) was 14 (range, 7-31). Among the 37 items comprised in the statement, 11 were sufficiently reported (reporting rate, >80%), whereas 19 were inadequately reported (reporting rate, <30%). Under-reported items were mainly associated with open science and key methodological domains. For the STRICTA reporting standards, the reporting quality of RCTs was satisfactory, with a median QS of 9 (range, 4-13). Only four of the 17 items in STRICTA were under-reported, and the setting and context of treatment had the lowest reporting rate (2/57). The CONSORT-Outcomes-based median QS was 8 (range, 5-16). Among the 17 items, 5 were well reported, and 10 were poorly reported. In addition, RCTs published in English and funded studies had higher reporting quality.RCTs of acupuncture for LBP should focus more on reporting open science, key methodology, details of acupuncture and comprehensive outcome-related information. Authors and journals, especially those in China, need to strengthen their adherence to the CONSORT statement and its extensions to enhance the reporting quality of RCTs.© Author(s) (or their employer(s)) 2025. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ Group.