Background: Neutrophil gelatinase associated lipocalin (NGAL), an acute phase protein expressed in endothelial cells and macrophages in atherosclerotic plaques, may be involved in development of atherosclerosis via endothelial dysfunction, inflammatory processes and matrix degradation leading to atherosclerotic plaque instability by modulating the activity of metalloproteinase 9. Our aim was to correlate urine NGAL with complexity and severity of angiographic lesions in patients of STEMI. Methods and Materials: We prospectively included 50 STEMI patients who underwent primary angioplasty. Urine NGAL, other inflammatory markers and biochemical parameters were measured on admission. According to SYNTAX score the STEMI patients were divided into two groups: Low SYNTAX score (≤ 22), intermediate- high SYNTAX score (>22). Results: In our study, majority of STEMI patients (76%) had lower NGAL level (<50 ng/ml). Urine NGAL level showed significant increased trend as duration of angina increases (p=0.011). NGAL was significantly reversely correlated with LVEF (p= 0.04). Patients with deranged renal function (creatinine ≥ 1.5 mg/dl) had significantly higher NGAL values (≥50 ng/ml p=0.011). Although in STEMI, NGAL was not significantly correlated with number of vessels involved, but patients with high SYNTAX score (>22) had significant higher NGAL values (≥50 ng/ml p=0.012). Conclusion: NGAL is a novel biomarker which predicts severity and complexity of angiographic lesions in patients of STEMI.