There is growing evidence of the clinical significance of daytime masked hypertension (MHT) and blood pressure (BP) variability (BPV). Recently, watch‐type wearable devices for self‐BP measurement have become available. Such devices might be promising tools to identify patients with daytime MHT or large BPV in their real‐life conditions. The present study aimed to validate the accuracy of the Omron HEM‐6410T‐ZM and the Omron HEM‐6410T‐ZL, which are automatic watch‐type wearable devices for self‐BP measurement, according to the American National Standards Institute, Inc/Association for the Advancement of Medical Instrumentation/International Organization for Standardization (ANSI/AAMI/ISO) 81060‐2:2013 guideline. Watches were held with the wrist at heart level. The mean differences between reference BPs and HEM‐6410T‐ZM readings were −0.9 ± 7.6/‐1.1 ± 6.1 mm Hg for systolic BP (SBP)/diastolic BP (DBP) for criterion 1, and −0.9 ± 6.8/‐1.1 ± 5.5 mm Hg for SBP/DBP for criterion 2. The mean differences between reference BPs and HEM‐6410T‐ZL readings were 2.4 ± 7.3/0.7 ± 7.0 mm Hg for SBP/DBP for criterion 1, and 2.4 ± 6.5/0.7 ± 6.5 mm Hg for SBP/DBP for criterion 2. The Omron HEM‐6410T‐ZM and the Omron HEM‐6410T‐ZL both fulfilled both validation criteria 1 and 2 of the ANSI/AAMI/ISO 81060‐2:2013 guidelines.