AIMS/INTRODUCTION: This study examined the effect of daily walking steps on glycated hemoglobin, body mass index (BMI) and body composition while taking into consideration sedentary time (ST) in Japanese type 2 diabetes patients over a period of 12 months. MATERIALS AND METHODS: Self-administered ST values and information regarding daily walking steps were obtained and analyzed for 236 patients with type 2 diabetes who regularly visited the outpatient clinic. The patients - divided into three categories of daily walking steps: non-step counter user, <7,500 daily walking steps and ≥7,500 daily walking steps (HS) - were prospectively observed considering ST through the monitoring of glycated hemoglobin, BMI waist circumference (WC) and visceral fat accumulation (VFA) for 12 months. RESULTS: After 12 months, the participants categorized as the HS group had significantly reduced BMI and VFA independent of ST, as well as significantly reduced WC with high ST. WC and VFA disparities widened significantly at 12 months between the participants categorized as being in the non-step counter user group and the HS group with long ST. However, no difference in glycated hemoglobin levels and BMI were found among the three categories independent of ST. Compared with non-step counter users, the odds ratios with logistic regression models of improvement in BMI and VFA in the <7,500 daily walking steps and HS groups, and WC in the HS group after 12 months were significantly higher only among those with long ST. CONCLUSIONS: These results suggest that consideration of sedentary behavior in combination with daily walking steps might be essential for type 2 diabetes management.