Numerical and analytical solutions for the backscattered pulse shape from a slab of random medium are given based on the cumulative forward‐scatter single‐backscatter (CFSB) approximation given by deWolf, assuming small angular‐spread and a narrow‐band incident pulse. The analytic solutions for asymptotic limits for extreme small‐angle scattering are also obtained. The results are applicable to both discrete media with large particles and continuous media with a large scale of t