Background: Patients with chronic diseases are in need of regular health controls. Diabetes mellitus type 2 is currently the mostprevalent chronic metabolic disease. A majority of diabetic patients have at least one comorbid chronic disease, where hypertensionis the most common. The standard for blood pressure (BP) measurement is manual BP monitoring at health care clinics.Nevertheless, several advantages of self-measured BP have been documented. With BP data transfer from an automatic BPmonitor via Bluetooth to software, for example, a smartphone app, home measurement could effectively be integrated into regularcare.Objective: The aim of this study was to validate two commercially available automatic BP monitors with the ability to transferBP data via Bluetooth (Beurer BM 85 and Andersson Lifesense BDR 2.0), against manual BP monitoring in patients with type2 diabetes.Methods: A total of 181 participants with type 2 diabetes were recruited from 6 primary care centers in Stockholm, Sweden.BP was first measured using a manual BP monitor and then measured using the two automatic BP monitors. The mean differencesbetween the automatic and manual measurements were calculated by subtracting the manual BP monitor measurement from theautomatic monitor measurement. Validity of the two automatic BP monitors was further assessed using Spearman rank correlationcoefficients and the Bland-Altman method.Results: In total, 180 participants, 119 men and 61 women, were included. The mean age was 60.1 (SD 11.4) years and themean body mass index was 30.4 (SD 5.4) kg/m2. The mean difference between the Beurer BM 85 and the manual BP monitorwas 11.1 (SD 11.2) mmHg for systolic blood pressure (SBP) and 8.0 (SD 8.1) mmHg for diastolic blood pressure (DBP). Themean difference between the Andersson Lifesense BDR 2.0 and the manual BP monitor was 3.2 (SD 10.8) mmHg for SBP and4.2 (SD 7.2) mmHg for DBP. The automatic BP measurements were significantly correlated (P<.001) with the manual BPmeasurement values (Andersson Lifesense BDR 2.0: r=0.78 for SBP and r=0.71 for DBP; Beurer BM 85: r=0.78 for SBP andr=0.69 for DBP).Conclusions: The two automatic BP monitors validated measure sufficiently accurate on a group level, with the AnderssonLifesense BDR 2.0 more often falling within the ranges for what is acceptable in clinical practice compared with the Beurer BM85.