Introduction: Amblyopia is the leading cause of preventable monocular vision loss in children. Refractive error is a common cause of amblyopia, other causes being anisometropia, ocular media opacities, strabismus or a combination of factors. Since amblyopia is avoidable and treatable, early screening and timely treatment are very important.Objectives: To assess the prevalence and types of amblyopia among 6-15 years old school going children in urban West Bengal, India.Method: A cross sectional study was conducted for one year among 3882 rural school children aged 6-15 years. A full ophthalmic examination, including refraction, fundoscopy and slit lamp examination was done in children having vision <6/12 without any organic lesion.Results: Amblyopia was found in 112 (2.9%) children. Common causes of amblyopia observed were anisometropia (33.9%), strabismus (29.5%), meridional amblyopia (14.3%) and combined (13.4%). Amblyopia was higher in males (3.2% vs 2.5%) and in the 11-15-year age group (3.1% vs 2.6%), though it was not statistically significant.Conclusions: Prevalence of amblyopia was 2.9% in our study population and anisometropia was the commonest (33.9%) type.