Dapagliflozin, a selective inhibitor of sodium glucose co-transporter 2 (SGLT2), is a novel glucose-lowering agent that has pleiotropic actions on blood pressure and lipids. Its glucose-lowering effect is not mediated by insulin. We report a type 2 diabetic patient whose blood pressure pattern improved from non-dipper to dipper after treatment with dapagliflozin. The 60-year-old man was treated with 5 mg/day dapagliflozin, and the effect of treatment on his blood pressure (BP) was evaluated by ambulatory blood pressure monitoring (ABPM) before and at 8 and 14 days after the start of treatment. The 24-h systolic blood pressure/diastolic blood pressure decreased from 131/87 to 127/83 mmHg at day 14, with a particular decrease in nocturnal blood pressure from 123/84 to 116/75 mmHg (nocturnal blood pressure dip increased from 9.6% to 12.8%), changing from a non-dipper to a dipper blood pressure pattern. Dapagliflozin might potentially improve not only the average blood pressure, but also nighttime blood pressure from non-dipper to dipper in type 2 diabetic patients.