1. Method for automatically executing the measurement of at least one geometric dimension of an object having arrangement, with respect to the dimension to be measured, that is unknown beforehand; the measurement occurring with optical means ( 2 ) and with means ( 5 ) for gripping the object and comparison means ( 4 ) and electronic control means ( 7 ), characterized in that it provides for detecting at least one first image of the arrangement of the object, verifying said arrangement as a function of a first condition identifiable beforehand by means of one or more references thereof, and in case of lack of correspondence, automatically carrying out the adjustment of the orientation of the object by means of relative movement between the means ( 2 ) and ( 5 ); said movement being provided along any one spatial direction and/or rotation being provided according to any one rotation axis; upon reaching said first condition, proceeding with the measurement of at least one geometric dimension of the object.