Recent studies have shown that variability in home blood pressure has an important role in the progression of organ damage. The objective of this study was to investigate the factors that affect variability in home blood pressure in patients with type 2 diabetes. We assessed the relationship between home blood pressure variability, defined as coefficient of variation of mean of triplicate morning and evening blood pressure for 14 consecutive days, and various factors using univariate and multivariate linear regression analyses in 1114 patients with type 2 diabetes. Age (β=0.149, P<0.001), female sex (β=0.125, P=0.010), duration of diabetes mellitus (β=0.103, P=0.005), heart rate (β=0.136, P<0.001), current smoker (β=0.118, P=0.005), white-coat hypertension (β=0.136, P=0.002) and treatment with calcium channel blockers (β=-0.094, P=0.024) were independently associated with coefficient of variation of morning systolic blood pressure. Our findings implicate that factors that might be intervened such as heart rate, smoking status, use of antihypertensive medication in addition to age, sex and duration of diabetes mellitus are associated with variability in home blood pressure in patients with type 2 diabetes.