Abstract Aims/Introduction There is potential for mobile applications to deliver new self‐management interventions for chronic disease, especially in diabetes. The aim of the present study was to evaluate the effects of a mobile phone application (MPA) combined with or without self‐monitoring of blood glucose (SMBG) on glycemic control in patients with diabetes. Materials and Methods The study was a 24‐week period, four‐arm parallel group, non‐blinded, randomized trial. A total of 185 patients with mean age of 52 years were randomized to group A (no MPA and no SMBG), group B (SMBG only), group C (MPA only) and group D (both MPA and SMBG were used). Changes in glycated hemoglobin (HbA1c), fasting plasma glucose and 1,5‐anhydroglucitol from baseline to week 24 were analyzed. Results At 24 weeks, the HbA1c levels in patients of all groups decreased significantly from baseline. There were significant differences in the proportions of patients that achieved HbA1c