<b>Introduction and Objective:</b> Low peak inspiratory flow rate (PIFR) can cause suboptimal inhaler usage, leading to ineffective bronchodilation.<sub>1</sub> This study aim was to determine the frequency of PIFR with a manual inspiratory flow meter in patients using inhaler devices. <b>Methods:</b> A descriptive, cross-sectional study including adult patients assisting lung function laboratory on their routine follow-up of their chronic respiratory disease using inhaled medication. In-Check DIAL G16® device was used to simulate the resistance of the inhaler and determine the patient’s PIFR. <b>Results:</b> Total number was 155 patients, mean age of 63±15.2 years, 58.1% women. 64 (41.3%) patients used inhalers with an optimal PIFR greater than 60 L/ minute. The specific values of each one are observed in table 1, finding statistically significant differences by both group comparisons (p <0.01). Good correlation was found when PIFR was compared with peak inspiratory flow measured in liters with spirometry (r<sup>2</sup> Pearson= 0,724; p<0,05). <b>Conclusions:</b> Low PIFR was frequently determined in patients using various inhalers devices, and consequently, not reaching its optimal value for adequate treatment. 1Kawamatawong T., et. al. Peak inspiratory flow rate measurements by using In-Check Dial for the different inhaler devices in elderly with obstructive airway diseases. Journal of Asthma and Allergy 2017: 10; 17-21.