Chlamydia pneumonia infection has been suggested to play a role in pathogenesis of asthma. This study included 50 asthmatic patient divided into 2 groups. Group (1) composed of (20) new wheezers, Group (2) composed of (30) chronic asthmatic children. Also 20 healthy children were included as a control group .All cases were subjected to the routine laboratory investigations, IgE, and qualitative estimation of C.pneumonia infection in nasopharyngeal swabs, using (P.C.R) technique. Our results revealed the presence of C.pneumonia in 40% of group (1) and in 30% of group (2) and 10% of control. No significant statistical differences between P.C.R (+) and (-) patients as regards age, asthma severity, medication plan or IgE level. There were significant differences as regards P.E.F.R and sex of the patients.