Unfortunately asthma is one of the most common chronic diseases worldwide and the prevalence is increasing, especially among children. The prevalence of asthma symptoms in children varies from 0.30 % in different population with the highest prevalence occurring in Australia, New Zealand and England. The objective of present work is to purify Montelukast and its intermediate stages with improved potency, better compatibility to human body, greater bio availability and lesser serious side effects.Quality improvement(Purification) can be achieved by various methods, like chromatographic techniques, crystallization by salt formation and its reversal back to active pharmaceutical ingredient and simple re-crystallization. So, purification or quality improvement of any drug is the necessity for safety of human life.