Abstract: This paper presents a parallel phase zero estimation framework to compute the axial tissue displacements. The framework includes two independent steps: coarse motion estimates and motion estimate refinement. For two frames of baseband signals, coarse motion estimates are first computed by using cross correlation function. The obtained motion estimates are used as initial guess for phase zero estimation. Then, the 2D phase zero estimation method is employed to refine the motion estimates. The experimental results illustrated that the two-step parallel estimation strategy is capable of generating fine motion estimation and is also suitable for parallel computation. Compared with the standard phase zero estimation method based on CPU, the proposed parallel estimation framework based on GPU achieved 7 times speed-up. In conclusion, the proposed parallel estimation framework not only obtains the fine elastogram, but also improves the computational efficiency.