The density and velocity fields as extracted from the Abell/ACO clusters are compared with the corresponding fields recovered by the POTENT method from the Mark III peculiar velocities of galaxies. In order to minimize non-linear effects and to deal with ill-sampled regions, we smooth both fields using a Gaussian window with radii ranging between 12 and 20 h−1 Mpc. The density and velocity fields within 70 h−1 Mpc exhibit similarities, qualitatively consistent with gravitational instability theory and a linear biasing relation between clusters and mass. The random and systematic errors are evaluated with the help of mock catalogues. Quantitative comparisons within a volume containing ∼12 independent samples yield βc≡Ω0.6bc=0.22±0.08, where bc is the cluster biasing parameter at 15 h−1 Mpc. If bc∼4.5, as indicated by the cluster correlation function, our result is consistent with Ω ∼ 1.