Objective: To investigate the long-term (>12 months) effectiveness of conservative management for lateral epicondylitis. Data Sources: PubMed and Embase databases were searched for relevant studies from inception to March 2023. Study Selection and Data Extraction: Only English-written randomized controlled trial (RCT) with data download as well as follow up >= 12 months were acceptable. Raw data were extracted into a predefined worksheet, and quality analysis was conducted based on the Cochrane risk-of-bias tool version 2 (RoB2). Data Synthesis: The standardized mean difference (SMD) with 95% confidence interval (CI) were calculated. Results: Extracorporeal shock wave therapy (ESWT) could significantly relive pain for lateral epicondylitis patients in the long term (SMD: -0.19, 95% CI [-0.36, -0.02]); however, there was no significant difference between ESWT and control groups in long-term function outcome (SMD: 0.24, 95% CI [-0.02, -0.49]). No significant difference could be observed between (1) exercise and control groups in pain (SMD: -0.21, 95% CI [-0.60, 0.18]) or function (SMD: 0.06, 95% CI [-0.11, 0.23]), (2) corticosteroids and placebo groups in pain (SMD: 0.70, 95% CI [-0.43, 1.82]) or function (SMD: -0.02, 95% CI [-0.36, 0.31]), and (3) platelet-rich plasma (PRP) in pain (SMD: -0.30, 95% CI [-0.85, 0.25]) and function (SMD: -0.08, 95% CI [-0.78, 0.62]). Conclusion: The present conventional conservative management for lateral epicondylitis, with the exception of ESWT, a lack adequate evidence supporting their long-term effectiveness.