Reversibility testing is typically positive in asthmatic patients showing obstructive pattern on spirometry; however, few studies evaluated this test among overweight and obese patients presenting with non-obstructive patterns. A sample of 218 overweight and obese adult asthmatic patients who satisfactorily completed spirometry and bronchodilator reversibility testing were selected for analysis. A portable spirometer (All flow, Clement Clarke International, UK) was used for measurement of lung ventilator function for each patient before and after inhalation of four separate doses of 100μg salbutamol given by a metered dose inhaler and using a spacer. Female to male ratio was 1.9:1. BMI (mean (SD)) was 31.6 (4.7). About one third of patients showed positive reversibility testing. Among these, more than one third (38%) had restrictive pattern, one third (33%) had combined pattern, 22% had obstructive pattern and only 7% had normal pattern (P= 0.000). Statistical differences between males and females in both spirometric patterns and reversibility testing were insignificant (P= 0.822 & 0.082 respectively). Reversibility testing was found to be positive in a significant proportion of overweight and obese asthmatic patients presenting with non-obstructive patterns on spirometry. The diagnosis of asthma can be confirmed with positive reversibility testing irrespective of spirometric pattern.