The wing of an aircraft undergoes complex flow phenomena which affect the aerodynamics performance. Tip vortex formation and wake developments are two of the main factors affecting the aerodynamic performance. Winglets have been used to mitigate the tip vortex formation and improve the wing aerodynamic performance. In the present research we study the aerodynamic performance of single and double-winglets. The numerical computations are carried out using the large eddy simulation (LES) approach. The aerodynamic performance of single and double-winglet designs are compared. The preliminary results show that the double-winglet improves the aerodynamic performance of the wing by increasing the lift coefficient and reducing the tip vortex formation.