Background: The present study assessed the association between relative handgrip strength (RHGS) and hypertension incidence in healthy adults. Methods: We performed a case-cohort study on 3784 participants from Ravansar Non-Communicable Diseases cohort study. The absolute HGS was measured using a digital dynamometer. Hypertension was defined as systolic/diastolic blood pressure ≥140/90 mm Hg and/or use of antihypertensive medications. Cox regression analysis was utilized to estimate hazard ratios of incident hypertension events with RHGS. Results: Physical activity was significantly higher in the participants with hypertension compared with nonhypertensive participants (P < .001). High-level physical activity in the subjects with lower, middle, and upper RHGS was 19.6%, 33.1%, and 47.3%, respectively (P < .001). RHGS was significantly higher in individuals with greater skeletal muscle mass (P < .001). The men and women with the upper RHGS, had an 80% (hazard ratio: 0.2; 95% confidence interval, 0.1–0.3) and 70% (hazard ratio: 0.3; 95% confidence interval, 0.1–1.2), were lower risk of hypertension compared with those with the lower RHGS, respectively. This association remains significant after adjustment for confounding factors in men. Conclusion: The study demonstrated that middle and upper levels of RHGS were associated with a lower risk of hypertension incidence. RHGS may be a protective factor for hypertension. We suggested muscle strengthening exercises.