A method for installing a monitoring device in a tire for vehicle wheels, includes: providing a monitoring device including: an electronic unit; a connecting member having an upper structure and a lower structure that, in cooperation, define a housing for the electronic unit, the lower structure including two base portions mutually separated by a separation region, each of the base portions having a respective base surface associable with an inner surface of a tire. The method further includes providing a positioning device including two separate active portions, each having a main surface in the shape of which matches that of a respective portion of an outer surface of the monitoring device, the separate active portions being adapted to cooperate with at least the base portions; associating the positioning device with the monitoring device to keep the monitoring device in an installation condition in which the base portions are maintained at a given mutual distance by the active portions; fastening the base portions to the inner surface of the tire; and removing the positioning device.