In this paper, a fractal model is presented for the starting pressure gradient for Bingham fluids in porous media embedded with fractal-like tree networks. The proposed model relates the starting pressure gradient to the structural parameters of porous media and microstructural parameters of the fractal-like tree networks, the yield stress and fractal dimensions. The model predictions from the present model for the starting pressure gradient are compared with the available expression. Good agreement is obtained between the predictions by the proposed expression Eq. (17) for the starting pressure gradient with those from the available expression. (C) 2011 Elsevier Ltd. All rights reserved.