Flow separation affects the aerodynamic performance of the Airfoil. The bio-inspired Airfoil with leading-edge tubercles is effective in controlling separation at a higher angle of attack. In the present study, a photoluminescent pigment is used to capture the flow features due to the leading-edge sinusoidal tubercles. The tubercles geometry for amplitude (A) of 1.65, 4.38, and 9 mm are used to maintain the wavelength (λ) of 16.5 mm to achieve the required A/ λ ratios. A NACA 0020 airfoil geometry is used and its leading edge is replaced with sinusoidal tubercles of specific geometry. Experiments are conducted in a wind tunnel facility for an air velocity of 10 m/s for a test model set for an angle of attack from 0 to 20°. The flowvisualized images captured the formed laminar separation bubble (LSB) and the counter-rotating vortex pair (CRVP). It is observed that as the amplitude of the tubercle is increased, the suction side is covered by the LSB decreases and flow reattaches. As the amplitude increases the CRVPs start forming at lower angles of attacks and move towards to leading edge by reducing their sizes.