This paper introduces a finite volume method to solve 2D steady state convection-diffusion problems on structured non-orthogonal grids. Overlapping control volumes (OCV) are used to discretize the physical domain and the governing equations are solved without transformation. An isoparametric formulation is used to compute diffusion and for upwinding. Four test problems are solved using this and other schemes. The modelling of diffusion in OCV seems very effective even on distorted meshes. The convection modelling in OCV is found to be second-order-accurate, like QUICK, on regular meshes. Although its accuracy is slightly inferior to the latter on rectangular grids, its faster convergence gives it a better overall performance. On non-orthogonal grids, OCV gives better accuracy for a large and practical range of Peclet numbers than does QUICK applied to the transformed equations using the conventional five-point diffusion modelling. The results obtained also demonstrate that the scheme reduces false diffusion to a considerable extent in comparison with the power-law scheme.