The speckle pattern in ultrasound imaging reduces image quality. The Thomson's multitaper approach smoothes the speckle but one drawback is the decrease of the spatial resolutions. It is shown in this paper that the combination of Pulse Inversion and Thomson's multitaper techniques called Multitaper Pulse Inversion (MPI) can reduce speckle noise and limit the resolution loss on second harmonic images in simulations and acquisitions.