Background The aim of the present study was to measure peripheral blood flow (BF) with a new finger-occlusion plethysmograph (FOP) and to compare this to BF measured with a laser Doppler flowmeter (LDF). An additional objective was to investigate the relationship between hypertension-related clinical parameters and peripheral vascular resistance (PVR) estimated from BF and mean blood pressure (BP) (PVR = mean BP/BF) in young subjects. Methods and Results The present study employed 101 young volunteers (61 males, 40 females, mean age 23.2±2.5 years). The FOP was attached to the third finger and an LDF to the fourth fingertip of each subject. BF was measured simultaneously by the 2 devices. A multi-biomedical recorder (TM2425) measured 24-h BP. A high correlation was observed between BF measured by the FOP and LDF (r=0.79, p<0.001). In multiple linear regression analysis, PVR was independently correlated with a family history of hypertension (p<0.01) and with base diastolic BP during sleep (p<0.01), which is a sensitive predictor of severity of hypertension. Conclusions Our newly developed FOP can estimate peripheral absolute BF easily. Furthermore, BF determined by the FOP can be used to calculate PVR, and an elevated PVR may be a useful predictor of hypertension. (Circ J 2008; 72: 1329 - 1335)