Background Home blood pressure monitoring (HBPM) could improve blood pressure control through therapeutic adherence. The main objective of this study was to determine the link between HBPM used by hypertensive patients treated in primary care and their medication adherence. Methods Cross-sectional comparative study conducted in the Auvergne region from June to November 2016. Patients were recruited by general practitioners (GPs) selected at random. Adherence was evaluated according to the Girerd score. Results From a sample of eighty-two GPs including 1026 patients, 45% of patients reported owning an HBPM device. Among these, 18% knew the rule of 3 (3 measurements in the morning and 3 in the evening for 3 days) recommended by the French State Health Authority. There was no difference in adherence between patients using HBPM and those who did not. Patients with HBPM using the rule of 3 reported better adherence than patients without the device (p = 0.06), and those who did not perform self-measurements according to the rule of 3 (p = 0.01). Patients who used HBPM according to the rule of 3 were older (p = 0.006) and less smokers (p = 0.001) than the others. Their GPs were more often GP teachers (p < 0.001) who practiced in rural areas (p = 0.001). Conclusion The statistical link between medication adherence and HBPM for patients who apply the rule of 3, emphasizes the importance of the GP educating the patient on the proper use of HBPM.