High-quality epitaxial thin films (∼200nm thick) of Gd0.67Ca0.33MnO3 have been deposited onto (100) SrTiO3 substrates by pulsed-laser deposition. Enhanced properties in comparison with bulk samples were observed. The magnetic transition temperature (Tc) of the as-grown films is much higher than the corresponding bulk values. Most interestingly, magnetization measurements performed under small applied fields, exhibit magnetization reversals below Tc, no matter whether the film is field cooled (FC) or zero-field cooled (ZFC). A rapid magnetization reversal occurs at 7K when field cooled, while as for the ZFC process the magnetization decreases gradually with increasing temperatures, taking negative values above 7K and changing to positive values again, above 83K. In higher magnetic fields the magnetization does not change sign. The reversal mechanism is discussed in terms of a negative exchange f-d interaction and magnetic anisotropy, this later enhanced by strain effects induced by the lattice mismatch between the film and the substrate.