The synthesis conditions, certain problems of epitaxial growth, and methods of controlling the quality of single-crystal iron-garnet films are discussed. The main physical properties of garnet films are considered, such as optical absorption, Faraday rotation, the characteristic length, the saturation magnetization, the coercive force, the magnetic anisotropy, the mobility, and the dynamic transformation of domain walls. Measurement methods and some results of the investigation of these properties are described. The reproducibility and the temperature dependence of the principal parameters of the films are discussed.