The study was aimed to compare FEV1 &PEFR measurements in suspected asthmatic patient, to determine whether PEFR is also sensitive enough for challenge test in children with suspected asthma, and to study FEV1 or PEFR or both will be helpful in diagnosing asthma. Study was performed on 50 suspected childhood asthmatic (H/o episodic cough & wheeze)referred from paedriatic OPD ; aged 5-14 yr both male and female through Simple Random sampling .Test procedure was explained ,consent taken, performance of FEV1 and PEFR through PFT and peak flow master recorded. Subjects with FEV1 >80% predicted with no increase in symptoms (n=50) directly underwent exercise challenge test in form of spot jogging double the pulse rate, FEV1<80% predicted with increased symptoms (n=0) were given salbutamol inhalation before exercise challenge test. Post test spirometry and peak flow master values recorded. Statistical Software EPI INFO, version 3.4.3, paired “t” test, unpaired “t” test were with 0.05 as level of significance used, there was a good correlation found between FEV1 Pretest vs. PEFR Pretest, FEV1 Post test vs. PEFR Post test, Pretest PEFR (master) vs. Pretest PEFR (PFT), Post test PEFR (master) vs. Post test PEFR (PFT).Comparing PEFR measurement obtained through spirometer and peak flow meter was 0.04 which is significant. Hence concluded that PEFR is sensitive to air flow, PEFR master can be a tool in measuring lung function. PEFR master could be alternatively used in place where spirometer cannot be carried