The effect of maldistribution of liquid and vapor in a column with random packing is terms of its effect on the specific pressure drop (Delta p/H),(2 phi), the HETP, and the total accomplish a given separation. A percolation model for the pressure drop has been used where, discussed and quantified in pressure drop Delta p(2 phi), required to the hydraulic calculations presented although other available models could also be applied. The HETP at total reflux was estimated with the Fenske equation. These particular simulations demonstrate that the specific pressure drop (Delta p/H)(2 phi), the RETP and the total pressure drop Delta p(2 phi),, are sensitive functions of the degree of maldistribution as well as of the degree of separation desired. We further demonstrate that local operating line-equilibrium curve pinches can develop even at total reflux in the presence of maldistribution, and that these pinches further exasperate the reduced column performance due to the maldistribution alone. Finally, a differential equation relating the liquid and vapor distributions within the column is elaborated. This equation has as its basis the assumption that the radial pressure gradient within the column is, on average, zero.