The Historic Museum in Przasnysz as a branch of The Regional Museum in Ostrołęka was established on 1 June 1983 after nationalizing a social Muzeum of Przasnyska Land. This museum existed since 1980 under the auspices of the Association of Przasnyska Land Friends. The museum gathers collections in two departments: archeological and historical.

The archeological relics are neolithic axes, hatchets, flint and stone arrow-heads, flint splits, arrow-heads for spears.

In a historic department there are collected exhibits and archives concerning the history of Przasnysz and the region with a particular consideration of the past of craft and trade. Among the collections there are coins, notes, awards and medals, militarias, craftwork. To the very vulnerable relics one should encounter flags of gilds from Przasnysz: smiths and goldsmiths from 1866, carpenters from 1925, shoemakers from 1923. Among the iconographic collections there are - pictures, graphics, sculptures and bas-relifs. There are widely presented archiva e.g. craftmen's diplomas from Przasnysz from the period of II RP, documents issued by different institutions in Przasnysz at the beginning of XX century and in the period of twenty years between the wars, photographies widely illustrating signs of cultural and social life and photographies of old Przasnysz from the first half of XX century (mainly contemporary prints), ceremonies from local anniversaries.

Simultaneously with collecting and elaborating the exhibits, there is run an exhibiting and popularizing activity.

Till the end of 2000 there were collected 2210 relics.