Objective To observe the serum homocysteine (Hcy) levels in retinal branch vein occlusion (BRVO) patients with with hypertension or non-hypertension. Methods A total of 120 patients (120 eyes) with BRVO were divided into hypertension group [72 eyes, blood pressure 140 - 175/90 - 105 mmHg (1 mmHg=0.133 kPa)] and non-hypertension group (48 eyes, blood pressure 100 - 139/70 - 88 mmHg). According to the sex and age, 78 patients with hypertensive non-retinal vascular diseases and 48 patients with non-hypertensive and non-retinal vascular diseases were collected by a way of same-size ratio as hypertension control group and non-hypertension control group, respectively. Fasting venous blood was collected from all patients in the morning and serum Hcy levels were measured by rate method. The total Hcy concentration over 15.0 μ mol/L was defined as high level Hcy. Fasting serum glucose and fasting serum lipid were also measured. Measurement data among groups were compared with t test. Results The serum Hcy levels were (26.82±28.0), (8.39±3.11), (21.37±4.24), (9.25±3.31) μmol/L in the hypertension group, hypertension control group, non-hypertension group and non-hypertension control group, respectively. The serum Hcy levels of patients in the hypertension group was significantly higher than that in the hypertension control group (t=3.324, P=0.004). The serum Hcy levels of patients in the non-hypertension group was significantly higher than that in the non-hypertension control group (t=2.216, P=0.049). The serum Hcy levels of patients in the hypertension group was significantly higher than that in the non-hypertension group, but the difference had not statistical significance (t=0.581, P=0.566). Among 120 patients, there were 68 patients (56.67%) with high level of Hcy (40 patients in the hypertension group and 28 patients in the non-hypertension group). Among the 40 patients with high levels of Hcy in the hypertension group, 36 patients were older than 50 years old (90.00%) and 4 patients were less or equal than 50 years old (10.00%). Among the 28 patients with high levels of Hcy in the non-hypertension group, 16 patients were older than 50 years old (57.14%); 12 patients were less or equal than 50 years old (42.86%), whose indexes of serum glucose and serum lipid were not abnormal. There was significant difference in age distribution of patients with high level of Hcy between the hypertension group and the non-hypertension group (χ2=9.882, P=0.002), but there was no significant difference in sex distribution (χ2=2.052, P=0.216). Conclusions The level of serum Hcy increased both in BRVO patients with hypertension and non-hypertension. The indexes of serum glucose and serum lipid were not abnormal in BRVO patients aged less or equal than 50 years old with non-hypertensive except for the increase of serum Hcy level.