Beta-thalassemia trait (BTT) is a common genetic disorder in Mediterranean countries including Iran. Previous studies have shown the protective effect of BTT on myocardial infarction that may be due to lower cholesterol levels or lower arterial blood pressure in BTT subjects. This study was designed to analyze the effect of BTT on arterial blood pressure in young adults. Four-hundred and eight subjects who were referred to our clinic for premarriage screening of BTT (208 BTT as the case group and 200 normal subjects as the control group) were recruited. BTT was diagnosed by complete blood count, hemoglobin electrophoresis, and column chromatography. Blood pressure was measured twice with 20-min intervals by a medical barometer in the sitting position from left arm, and the average blood pressure was recorded as subject's blood pressure level. Mean systolic blood pressure in the control group was 122.8 mmHg as compared to 117.0 mmHg in the case group (P value = 0.249). Mean diastolic pressure was the same in both groups (76.7 mmHg in control group as compared with 77.5 mmHg in the case group) (P value = 0.433). Analysis of blood pressure by gender showed that male BTT subjects had a 10-mmHg lower systolic blood pressure than normal subjects (120.8 mmHg in the case group as compared with 130.7 mmHg in the control group). BTT has a protective effect on the development of hypertension in young male adults.