Objective: To compare the efficacy of intravenous magnesium sulfate andconventional treatment with conventional treatment alone in acute severe asthma in children ofage group 5 to 15 years known cases of bronchial asthma. Study design: Randomized controltrial. Setting: Indoor and outdoor patients of pediatrics department of DHQ hospital, Faisalabad.Duration: Six months. Results: In this study, 43.58%(n=17) in Exposed and 53.85%(n=21) inUn-exposed group were male and remaining 56.42%(n=22) and 46.15%(n=18) were females,mean pulse rate in both groups was recorded which shows 97.32+6.58 in Exposed Groupand 103.67+8.32 in Un-exposed Group, p value was calculated as 0.02, mean FEV1 rate inboth groups was recorded which shows 60.32+7.56 in Exposed Group and 54.07+6.43 in UnexposedGroup, p value was calculated as 0.03. Conclusion: We concluded that intravenousmagnesium sulfate along with conventional treatment is significantly better than conventionaltreatment alone for the management of acute severe asthma attack.