A quasi experimental study to assess the effect of Buteyko breathing technique on asthma control among children at selected hospital, Thrissur. The objective of the study was to assess the score of Asthma control among children in experimental and comparison group, evaluate the effect of Buteyko breathing technique on asthma control in experimental group and associate the score of asthma control among children with their selected socio demographic variable. Roy’s adaptation model was used as the conceptual framework. Pre test post test design was adapted to assess the effect of Buteyko breathing technique on asthma control and purposive sampling technique was used to select 60 children in the age group of 4-11 years (30 in experimental and 30 in comparison group) who fulfilled the inclusion and exclusion criteria from out-patient and in-patient department of Government General Hospital, Thrissur. The tool consists of semi structured questionnaire to assess the demographic variables of children and their parents. Childhood asthma control test was used as a tool to evaluate the effectiveness of Buteyko breathing technique in pre and post test level of asthma control. Reliability and validity of the tool was established. The pilot study was done for 6 subjects and found to be feasible. The main study was conducted from 2nd February to 3rdMarch 2019. The comparative study findings revealed that the calculated ‘t’ value of asthma control in both group was 7.22, whereas the table value t was 2.390 at 0.001 level of significance. The investigator analyzed the association of selected demographic variables with pre test score of asthma control. Among 12 selected demographic variables socioeconomic status of the child had an association with pre test score. Keywords: Buteyko breathing technique; Asthma control; Children; Childhood asthma control test.