BACKGROUND: Data regarding role of socioeconomic status (SES) as etiology and site of involvement of veins in hepatic venous outflow tract obstruction (HVOTO) is scarce and only described from Nepal. We prospectively evaluated the role of SES in patients with HVOTO. METHODS: 70 consecutive patients (41 females; mean age 29, range 3-65 years) with HVOTO were studied. Their clinical history, socioeconomic factors (income, education, and occupation), birth history, dietary factors, living standards, baseline characteristics, liver function, and clinical parameters were evaluated. RESULTS: Of the 70 patients analyzed, 48 (68.5%) had hepatic vein (HV) obstruction, 7 (10%) had isolated inferior vena cava (IVC) obstruction, and 15 (21.5%) had combined HV and IVC obstruction. Of the 10 patients belonging to the upper SES, 7 had isolated HV obstruction, and 3 had combined IVC and HV obstruction; no patient had isolated IVC obstruction. Of the 60 patients belonging to the lower SES, 41(68.4%) had HV obstruction, and 19 (31.6%) had IVC involvement with (n=12) or without (n=7) HV involvement. HV/IVC involvement did not correlate with setting of delivery (hospital vs. home), birth weight, birth complications, immunization in childhood, ventilation in house, water storage facilities, history of diarrhea, or diet. Patients with HVOTO living in a mud house had IVC obstruction more commonly than HV (6/22 vs. 4/48; P=0.04). CONCLUSION: Isolated hepatic vein obstruction is the most common site of obstruction in patients with HVOTO in India, even among those belonging to low SES. Patients with HVOTO living in a mud house have IVC obstruction more commonly. Other socioeconomic factors studied do not appear to correlate with the site of obstruction.