We conducted a meta-analysis of randomized controlled trials to examine the association of mobile phone intervention with net change in weight-related measures among overweight and obese adults. We searched electronic databases and conducted a bibliography review to identify articles published between the inception date of each database and March 27, 2014. Fourteen trials (including 1,337 participants in total) that met the eligibility criteria were included. Two investigators independently abstracted information on study characteristics and study outcomes. Net change estimates comparing the intervention group with the control group were pooled across trials using random-effects models. Compared with the control group, mobile phone intervention was associated with significant changes in body weight and body mass index (weight (kg)/height (m)(2)) of -1.44 kg (95% confidence interval (CI): -2.12, -0.76) and -0.24 units (95% CI: -0.40, -0.08), respectively. Subgroup analyses revealed that the associations were consistent across study-duration and intervention-type subgroups. For example, net body weight changes were -0.92 kg (95% CI: -1.58, -0.25) and -1.85 kg (95% CI: -2.99, -0.71) in trials of shorter (<6 months) and longer (>= 6 months) duration, respectively. These findings provide evidence that mobile phone intervention may be a useful tool for promoting weight loss among overweight and obese adults.