This invention relates to methods for measuring geometrical parameters of a wind turbine blade, the method comprising placing a surveying instrument with a view to the root of the blade and measuring the blade. Methods are described for measuring parameters such as the blade length, the blade bending, the twist and the alpha-angle of the blade. This is accomplished by the use of a surveying instrument by which is measured a number of points or markings on the root of the blade, the blade tip and/or some reference markings on the blade. The invention further relates to the use of a surveying instrument for measuring and/or marking geometrical parameters on a wind turbine blade and for measuring deformations of a wind turbine blade.