The computed orientation distribution of fibers immersed in laminar pipe flows showed that the longitudinal distributions are wide for small Reynolds numbers and become narrower with increasing Re . For low Re number, the axial orientation distributions are broad with almost no preferred orientations. For high Re number, the axial distribution becomes narrow, with sharp maxima. The mean values of the longitudinal orientation depend strongly on the Re number. The computed results are in qualitative agreement with relevant experimental results. The computed orientation distribution of fibers immersed in laminar pipe flows showed that the longitudinal distributions are wide for small Reynolds numbers and become narrower with increasing Re. For low Re number, the axial orientation distributions are broad with almost no preferred orientations. , the axial distribution becomes narrow, with sharp maxima. The mean values ​​of the longitudinal orientation depend strongly on the Re number. The computed results are in qualitative agreement with relevant experimental results.