Aim: We analyzed characteristics and completion status of Systematic Reviews (SRs) about regional anesthesia for acute perioperative pain relief registered in PROSPERO. Materials & methods: PROSPERO was searched on 5 January 2022. Characteristics of PROSPERO records, completion status and publication information were extracted. PubMed and Google Scholar were searched by 31 May 2022, for additional published SRs. The inconsistency of PROSPERO records' status was analyzed by comparing the most recent PROSPERO status with subsequent publication of completed SR. Time-to-publication was calculated. Results: Almost half of 174 included PROSPERO records (49%) were registered in 2021. A median of 3 (IQR: 2–4.75) authors, and a search of 4 information sources (IQR: 3–5) was planned. At first registration, 51 (29%) records had already started or completed formal screening. PROSPERO records included mostly adults (48%) undergoing trunk blocks (56%), with pain intensity (74%) as a main outcome. 147 (84%) PROSPERO records had a status “ongoing”. Yet, 71 (41%) PROSPERO records were completed SRs, published after a median of 291 days. Inconsistency in status was found in 34% of PROSPERO records. Conclusion: Despite an increase in PROSPERO registrations about regional anesthesia, most were not published, and a third had inaccurate status.