Epitaxial thin films of La0.67Ca0.33MnO3 were implanted with 30 and 100 keV 57Fe ions at different fluence values to achieve a uniform implant distribution. The resistivity of the film increases as fluence increases, but the peak resistivity temperature Tp does not change significantly for the as-implanted sample. Annealing of the implanted samples at 950 °C allows recovery of the structural properties of the films and leads to interesting properties: increase of the peak resistivity and of the colossal magnetoresistance values, and decrease of Tp. The decrease in Tp is of ∼130 K, and the increase in resistivity is almost a factor of 28 as compared to the as-implanted sample. © 2003 American Institute of Physics.