The effect of Polyox WSR-301 drag-reducing polymer on the rate of cementation of copper from copper sulfate solution over packed beds of zinc pellets was investigated. The mass transfer coefficient was found to increase with increasing superficial liquid velocity for solution free of polymer. The mass transfer data were correlated in the absence of drag-reducing polymer, using the following equation J(d) = 12.55 Re-0.5 for the conditions 10 < Re < 1970 and 1265 < Sc < 1393. In the presence of polymer, starting from a Reynolds number (Re) 550, the rate of mass transfer was found to decrease by an amount ranging from 7.5 to 51 % depending on Re and polymer concentrations. The percentage decrease in the rate of mass transfer increased with increasing Re, passed through a maximum at Re = 1400 and then decreased rapidly with further increase in Re.