Objective: To determine the effectiveness of telemedicine in the delivery of diabetes care in low- and middle-income countries. Methods: We searched seven databases up to July 2020 for randomized controlled trials investigating the effectiveness of telemedicine in the delivery of diabetes care in low- and middle-income countries. We extracted data on the study characteristics, primary end-points and effect sizes of outcomes. Using random effects analyses, we ran a series of meta-analyses for both biochemical outcomes and related patient properties. Findings: We included 31 interventions in our meta-analysis. We observed significant standardized mean differences of -0.38 for glycated haemoglobin (95% confidence interval, CI: -0.52 to -0.23; I 2 = 86.70%), -0.20 for fasting blood sugar (95% CI: -0.32 to -0.08; I 2 = 64.28%), 0.81 for adherence to treatment (95% CI: 0.19 to 1.42; I 2 = 93.75%), 0.55 for diabetes knowledge (95% CI: -0.10 to 1.20; I 2 = 92.65%) and 1.68 for self-efficacy (95% CI: 1.06 to 2.30; I 2 = 97.15%). We observed no significant treatment effects for other outcomes, with standardized mean differences of -0.04 for body mass index (95% CI: -0.13 to 0.05; I 2 = 35.94%), -0.06 for total cholesterol (95% CI: -0.16 to 0.04; I 2 = 59.93%) and -0.02 for triglycerides (95% CI: -0.12 to 0.09; I 2 = 0%). Interventions via telephone and short message service yielded the highest treatment effects compared with services based on telemetry and smartphone applications. Conclusion: Although we determined that telemedicine is effective in improving several diabetes-related outcomes, the certainty of evidence was very low due to substantial heterogeneity and risk of bias.