The present invention concerns an infusion device for liquid medicines and the like, including at least one main body associated with at least one tank of liquid medicine, at least one peristaltic pump having at least one rotor coupled with at least one press roller that can be pushed so as to engage with a tubular duct wound so as to form at least one complete ring, abutting on the inner wall of at least one casing of said peristaltic pump, and including two substantially adjacent portions of said tubular duct. The device includes one control processor, associated with the motor of the rotor, including means for adjusting the speed of the rotor suitable for increasing the speed of said rotor in at least one sector of the complete revolution carried out by said rotor.