The Poviat Committee of the Polish Workers ‘Party in Mrągowo was established on July 13, 1945. In December 1948, after joining the local organization of the Polish Socialist Party, it transformed into a Poviat Committee of the Polish United Workers’ Party in Mragowo. This structure functioned until mid-1975, when it was dissolved. After the liquidation of the district committee, all party organizations from the area of the abolished Poviat were subordinated to the Provincial Committee of the PZPR in Olsztyn. The total number of party members in the Poviat was systematically increasing from less than 1500 at the time of the establishment of the PZPR, to over 2600 at the time of the Poviat’s liquidation. The last reliable data from 1988 regarding the number of PZPR members was 1800. The largest party organization had the PZPR Municipal Committee in Mrągowo, gathering 40–50% of all party members in the aforementioned area. The PZPR organization in Mrągowo experienced two major organizational crises: in 1956 and in the years 1980–1982. The second of them brought losses, which proved to be impossible to mitigate. Individual branches lost up to 20% of their members, there was chaos in the organization and there were no people willing to perform party functions. The disintegration of the organization was halted in 1984–1986. In the last years of the PZPR (1987–1989) only its superior structures, i.e. committees, were active. The basic branches ceased operations well before the formal dissolution of the party.