Objective: Asthma is the most common chronic childhood disease being increasingly diagnosed in recent years. The objective of study was to determine the occurrence and risk factors of asthma and their association. Methods: The conceptual model adopted was based on epidemiological triad. Consecutive sampling technique was done to select 203 children of age group 6to 12 years attending OPD in Diamond Harbour District Hospital. The measuring tool used were record analysis, structured and semi structured interview schedule and physical assessment recording proforma. Validity of tool was done by seven experts. Reliability was established by inter rater method. Results: The occurrence of asthma was 21.2%. On analysis among risk factors exposure to tobacco smoking during pregnancy (OR 3.76), needed NICU admission(OR 3.1) low birth weight (OR 3.58),first born child(OR 2.5), hospitalization before 2 yrs of age due to RTI(OR 9.76), family H/O different allergic symptoms (OR 6.31), family H/O of asthma (OR 14.29), residence near busy road (OR 2.25) and industrial area (OR 5.02), overcrowding (OR 2.22), damp in bedroom (OR 2.02) presence of domestic animal (OR 2.72) had significant association. Smoke producing and mixed type cooking fuel (OR 7.46), overweight (OR 12.8), seasonal variation (OR 12.1) and different triggering factors (OR 17.59) were significantly associated. Conclusions: The occurrence of asthma was 21.2% which was much higher than previously reported. Age group 6-9 yrs was commonly affected. In this study males (26%) had higher asthma occurrence than the females (13.8%) and it was statistically significant (p=0.037).). The male: female ratio is 1.26: 1. Family history of asthma or allergy, previous hospitalization due to RTI, exposure to smoke and smoking were found to be significant risk factors for development of asthma.