Background <p>The clinical treatment of delayed healing/nonunion of bones is challenging, and traditional surgery combined with autologous cancellous bone (ACB) grafting has limitations, including donor site complications and poor functional prognosis. This network meta-analysis (NMA) aims to compare the efficacy and safety of bone morphogenetic protein (BMP), platelet-rich plasma (PRP), and bone marrow aspirate concentrate (BMAC) in the treatment of delayed union or nonunion.</p> Methods <p>Search was conducted in the PubMed, Web of Science, Embase, and Cochrane Library databases up to July 1, 2025. Randomized controlled trials (RCTs) evaluating the treatment of adult bone delayed healing/nonunion with PRP, BMP, or BMAC were included. The primary outcomes included healing time, healing rate, and the incidence of adverse events (AEs). NMA was performed using STATA 16.0, and the efficacy and safety of the interventions were ranked based on the surface under the cumulative ranking curve (SUCRA).</p> Results <p>A total of 15 RCTs involving 1286 patients were included. Compared to standard treatment (ST), both PRP and BMP interventions demonstrated shorter healing times and higher healing rates. The SUCRA ranking indicated that PRP + ACB (<i>P</i> = 93.6%) and PRP + BMAC (<i>P</i> = 91.6%) were most likely the optimal strategies for shortening healing time and improving healing rates, respectively. In terms of AEs incidence, PRP + BMAC showed the highest SUCRA probability for reducing AEs (<i>P</i> = 99.8%).</p> Conclusions <p>BMP and PRP significantly reduced the time to complete healing and improved healing rates compared to the ST group, without increasing the risk of AEs. Among combination therapies, PRP + ACB may have the greatest potential for shortening healing time, while PRP + BMAC may be optimal for improving healing rates and reducing AEs. However, large-scale RCTs are needed in the future to validate the best intervention strategies for different sites and patient subgroups.</p>