This paper addresses 3D reconstruction of human organs from a set of ultrasound images, assuming that the probe position and orientation is available. Unfortunately, pose measurement errors produce significant misalignments, which degrade the performance of the reconstruction algorithms. This paper proposes a method for correcting these distortions by estimating the true position and orientation of the ultrasound probe. This is achieved by a joint computation of the 3D data and probe parameters using a MAP criterion. An evaluation of the proposed algorithm by Monte Carlo method is included in the paper.