We consider a mixed finite-volume finite-element method applied to the Navier-Stokes system of equations describing the motion of a compressible, barotropic, viscous fluid. We show convergence as well as error estimates for the family of numerical solutions on condition that: (a) the underlying physical domain as well as the data are smooth; (b) the time step t and the parameter h of the spatial discretization are proportional, t ≈ h; and (c) the family of numerical densities remains bounded for t, h → 0. No a priori smoothness is required for the limit (exact) solution.