The paper presents battles for cities during the Mława–Elbląg offensive operation, conducted by units of the 5th Armoured Guard on January 17–26, according to the orders of Marshal Konstanty Rokossowski, who commanded the 2nd Belarusian Front, and Colonel General Vasily Wolski. The findings, based on the documentation of the Central Archives of the Ministry of Defense of the Russian Federation and related literature on the subject, present the daily battles for cities led by armoured units and their assigned support. The border territories they occupied, marching routes and combat operations are noted, alongside the problem raised by commanders of insufficient support for tanks with infantry forces. The article describes the occupation or capture of: Mława, Działdowo, Nidzica, Stębark, Ostróda, Iława, Morąg, Zalewo, Małdyty, Pasłęk, Młynary and Tolkmicko as well as the initial battles for Elbląg.