Aim: It was aimed to show the relationship between childhood asthma and C3435T multidrug resistance 1 gene polymorphism. Material and Method: Fifty eight children with asthma and 54 healthy children participated to the study. Chi-square and Fisher exact tests were used for statistical analysis. Results: Wild, heterozygous and homozygous polymorphism for multidrug resistance - 1 gene were found respectively in 12 (20.7%), 31 (53.4%), and 15 (25.9%) of children with asthma. In healthy children, wild, heterozygous, and homozygous polymorphisms were found respectively in 18 (33.3%), 28 (51.9%), and 8 (14.8%) participants. There was no statistical difference between asthmatic and healthy children in terms of multidrug resistance 1 gene polymorphism. Homozygous polymorphism was found higher in severe persistent group than moderate and mild persistent groups (p=0.001) and in girls than boys (p=0.001). Discussion: It may be said that the difference was resulted from severe persistent asthmatic patients. And this information helps clinicians to rank the patients in terms of asthma by looking multidrug resistance 1 gene when the patient was diagnosed as asthma. Hence, treatment of patients, especially with crucial degree may begin earlier and its long-term pursuance can be made. In addition, gender-specific treatment can be planned especially for female patients.