Solar jets observed with the Extreme Ultra-Violet Imager (EUVI) and CORonagraphs (COR) instruments aboard the STEREO mission provide a tool to probe and understand the magnetic structure of the corona. Since the corona is a low-beta plasma environment, jets during their propagation follow the magnetic field lines. We discuss the North-South asymmetry of the magnetic field of the Sun as inferred from the measurements of the deflection of polar jets when they propagate throughout the corona. We measured the position angle at 1 and at 2 solar radii for the 79 jets based on the STEREO ultraviolet and visible observations, and we found that the propagation is not radial. The average jet deflection is studied both in the plane perpendicular to the line of sight, and, for a reduced number of jets in the three dimensional (3D) space. The deflection of jets results to be larger in the North than in the South, with an asymmetry which is consistent with the N-S asymmetry of the heliospheric magnetic field inferred from the Ulysses in situ measurements.