The present study aimed to investigate the association between plasma brain natriuretic peptide (BNP) levels and systolic blood pressure (SBP) variability over a one-year period. Blood pressure was measured in 44 patients treated for hypertension (73±9 years old) at an outpatient clinic every one to two months over a one-year period. The standard deviation (SD) and the coefficient of variation (CV) were calculated to assess SBP variability. Mean SBP was also calculated over the year. Plasma BNP levels were measured at the end of the one-year period. BNP was found to correlate with mean SBP (r=0.599; P<0.001). However, BNP was not observed to be correlate with either the SD (r=0.219; P=0.153) or the CV (r=0.058; P=0.709) of the SBP. Multiple regression analysis revealed that only the mean values of SBP were independently associated with BNP (β=0.613; P<0.001). Thus, BNP was found to be correlated with mean SBP, but not SBP variability. In conclusion, plasma BNP levels may reflect the average SBP, but not SBP variability over the one-year period prior to the measurement of BNP in patients with hypertension.