The electrical and optical properties of rf magnetron sputtered films of amorphous hydrogenated silicon (a–Si:H) have been measured as a function of rf power, argon and hydrogen partial pressures, and target‐substrate distance. The properties of the deposited films show a very different dependence on preparation conditions than those prepared by nonmagnetron sputtering. The conductivity can be varied over ten orders of magnitude and the optical gap can be shifted by more than 1.0 eV by changing the deposition parameters. Furthermore, it is found that the electrical conductivity and optical band gap are strongly correlated. Thus, we have not been able to prepare undoped films with a given conductivity independently of the optical gap. The results of our measurments of the temperature dependence of the conductivity, the conductivity activation energy (&Dgr;E&sgr;), the shape of the optical absorption curve, and the optical gap (Eopt), suggest a direct connection between gap state density and the optical gap.