Mobile health (mHealth) intervention based on smartphone applications (apps) emerged as an important diagnostic measure to help improve diabetes care and self-management. Until today, no studies highlighted the effect of prescribable mHealth apps on diabetes mellitus (DM). Therefore, this study was designed to perform a systematic review and meta-analysis of randomized controlled trials (RCTs) to assess the effect of mHealth apps on DM patients. A systematic literature search in Embase, Medline, and Cochrane CENTRAL through Ovid was conducted to identify RCTs comparing mHealth apps with control (standard care). Mean difference (MD) with 95% confidence interval (CI) were calculated using the random/fixed effect model to evaluate the effect of mHealth apps on HbA1c, blood glucose (BG), and body mass index (BMI) in DM patients. Of 1086 retrieved articles, seven RCTs with 546 patients from four geographies (US, Europe, Australia and China) were included. Four studies reported outcomes of type 1 DM patients, two studies included type 2 DM patients and one study included both. Mean duration of DM was 5-18 years. The most commonly reported mhealth apps from included RCTs are DBEES, Glucose Buddy, Diabeo System, mDiab, Few Touch Application, Welldoc, or Welltang. Pooled results from the meta-analysis of included RCTs reported a significant improvement in HbA1c (MD: -0.42, 95%CI: -0.69, -0.16; P=0.002; I2=42%) and BG level (MD: -1.1, 95%CI: -1.75, -0.45; P=0.0009; I2=0%) with mHealth apps group as compared to control group. However, no significant improvement was observed in the BMI (MD: -0.9, 95%CI: -2.84, 1.03; P=0.36; I2=54%) with mHealth apps group when compared to control group. Meta-analysis of included RCTs suggested that mHealth apps used by the DM patients may improve HbA1c level and could be considered as an adjuvant to the standard self-management for the DM patients. Further studies are warranted to standardize the use of mHealth technology.