This paper concerns the three-dimensional block hydraulic conductivity of blocks of limited size in cross-bedded sediments of meandering rivers. Based on a simplified sedimentological model of a single point bar, a stochastic model is proposed to simulate the spatial distribution of core scale conductivities within point bar deposits. The required parameters for these simulations are obtained from actual hydraulic conductivity measurements and sedimentological field data. The simulations are then used to calculate the three-dimensional block conductivity tensor with a numerical upscaling procedure. The stochastic simulation model is used to investigate the influence of slope and aspect angle of the cross-beds and the core scale anisotropy ratio on the block hydraulic conductivity. It is expected that the off-diagonal elements of the block conductivity tensor generally cannot be neglected. The core scale anisotropy ratio, which reflects the small scale layering within the cross-beds, can potentially have a significant impact on the elements of the block conductivity tensor. ¿ American Geophysical Union 1994