Abstract We measured the magnetization M ( T , H ) and resistivity ρ( T , H ) of epitaxial c ‐axis oriented films of the metallic ferromagnetic perovskite La 2/3 Ca 1/3 MnO 3 as function of temperature and external magnetic field. The films were prepared by dc‐sputtering at high oxygen pressure onto (001) SrTiO 3 substrates without additional oxygen annealing. Ferromagnetic ordering was observed below a temperature T C ≈ 260 K where a negative magnetoresistance ratio of 50% was achieved in a magnetic field of 6 T. Above T C , the zero field resistivity exhibits polaron‐hopping like activated conduction. The relation ρ( T , H ) ∝ exp[‐ M ( H , T )/ M 0 ] observed below T C suggests a direct connection between magnetization and resistivity.