A method for determining an azimuth angle of a wind power installation is provided. The method includes attaching at least two global navigation satellite system (GNSS) receivers to a nacelle, comparing reception signals of the GNSS receivers, deriving the azimuth angle from the comparison. The at least two GNSS receivers may be attached to a wind measuring supporting frame. Provided is a method including attaching a telescopic sight to a nacelle, determining a bearing of a bearing object at a bearing angle, deriving the azimuth angle from a comparison of the bearing angle with coordinates of the bearing object and/or the wind power installation. The telescopic sight may be attached to a wind measuring supporting frame. The at least one GNSS receiver may be attached to a wind measuring supporting frame. A wind power installation is also provided.