The association between homocysteine and Sustained hypertension (HT) has been Studied. The aim of this study was to assess homocysteine levels in white coat hypertension (WCH) as ail indicator of increased risk in the development of cardiovascular diseases. WCH was defined as clinical hypertension and a daytime ambulatory blood pressure of < 135/85 mmHg. Plasma levels of homocysteine were determined in patients with WCH, hypertension, and normotension (NT). The study group included 100 subjects, 33 with WCH (16 males, 17 females) aged 49.1 +/- 1.9; 35 Sustained hypertensives (17 males,18 females) aged 48.5 +/- 1.7 and 32 normotensive control subjects (15 males, 17 females) aged 48.8 +/- 2.2. The Subjects were matched for age, gender, and body mass index. Patients with a smoking habit, dyslipidemia, or diabetes mellitus were not included in the Study. Homocysteine levels were analyzed by ELISA. Plasma homocysteine levels were significantly higher in the WCH group compared to the controls (12.32 +/- 1.07 versus 5.35 +/- 1.38 mu mol/L; P < 0.001) and the WCH group had significantly lower homocysteine values than the hypertensives (19.03 +/- 0.76 mu mol/L P < 0.001). Total cholesterol and triglycerides were not different among the groups. There were no statistically significant differences in urinary albumin excretion (UAE) or creatinine clearence between the three groups. Hypertensive retinopathy was observed in the WCH group, but Was less Severe and less frequent compared to HTs. LVM1 was greater in the WCH group compared to the NTs. but significantly less than HTs.