Immunity is responsible for the defense mechanism of the body but in case of autoimmune diseases, its role gets diverted. Like so many other diseases, asthma is also considered as one of the most common autoimmune diseases to be occurring in community. Asthma is defined as a chronic inflammatory airway disease that is characterized by airway hyper reactivity and mucus hypersecretion that result in intermittent airway obstruction. The incidence of allergic asthma has almost doubled in the past two decades. Although, precise causative mechanism of asthma is unknown, but several mechanisms have been proposed that is immunological, pharmacological and genetic mechanisms, and airway and neurogenic inflammation. The inflammatory process observed in the asthmatic patients is the final result of a complex network of interactions between various immunological cell lineages, its mediators and secreted substances. Thus, among the mechanisms proposed, the immunological one plays a key role. Through this article, we have tried to provide some insight into immunological mechanisms in pathogenesis of asthma.