The pressure drag exerted on two identical high idealised mountain ridges aligned perpendicular to the mean flow, with the second mountain lying directly downstream of the first, is investigated using a numerical model. The drag is measured for a variety of different distances between the two peaks, mountain heights and lengths and incident flows. Each two-mountain simulation has a companion single mountain simulation, with an identical mountain and identical upstream flow, with which to compare the drag. The maximum modelled drag in the two-mountain simulations is close to two times the drag in the single mountain case, while the minimum two-mountain drag is similar to that exerted on the single mountain. This change in drag is a result of the wake behind the first mountain reducing the speed of the flow impacting on the second mountain. A parametrization of this effect is suggested which combines the distance between the two mountain peaks, a measure of the velocity deficit in the wake of the first mountain and the wake decay-scale, a measure of the length-scale over which the flow perturbation generated by the first mountain decays downwind. Copyright © 2008 Royal Meteorological Society and Crown Copyright 2008, published by John Wiley & Sons, Ltd.