The seventeenth-century wooden church of St. Nicholas in G¹sawa is one of the most important testimonies of the cultural heritage of the Pa³uki region. Alongside the church in Tarnów Pa³ucki it is the oldest extant wooden church in Pa³uki and one of the oldest within the range of historical Greater Poland. The tower-less, single-nave object with a small distinct sacristy and porch, with boarding on the outside and plaster inside, and a solid slightly deformed at the beginning of the nineteenth century by the addition to the nave of an unproportionately large, brick cylindrical chapel, did not meet with greater interest on the part of researchers. Recorded in catalogues of monuments and locally issued publications concerning the history of the region the church was discussed laconically as an edifice with a uniform construction, erected in 1674 (as evidenced by the date inscribed on the bell of the rood arch beam), and founded by Kazimierz Brzechwa, the abbot of Trzemeszno. Recent thorough repairs revealed the heretofore concealed original appearance of the church. The removal of nineteenth–century boarding and plaster showed that the church in G¹sawa has a double, frame supporting structure of the roof, while the interior walls are covered by at least three layers of painted decoration. An analysis of the architectonic structure, dendrochronological examinations, an archival survey, and an initial analysis of the arrangement programmes of particular phases of the painted decoration permitted the assumption that the gable walls, the frame and the rafter framing date back to the seventeenth century, but do not share a joint origin. The oldest are the frame walls, probably a remnant of a church raised at the end of the first quarter of the seventeenth century. The date on the rood arch beam — 1674 — commemorates not the construction but the reconstruction of the object, partially destroyed during the Swedish wars. Up to the 1690s the church was a frame construction. From 1697 to 1699 the frame became encircled on the outside by a skeletal structure (without nogging). The most likely reason for this solution was the enlargement of the nave windows. The skeletal construction relieved the weakened frame and guaranteed stability to the static configuration of the edifice. The organic union of the frame and skeletal structure and the rafter framing made it possible to recognise the carrying systemof the roof as the effect of a well–devised architectonic conception. Up to now, literature concerning wooden churches has not distinguished the double, frame–skeletal, construction of the walls. Similar solutions have been recorded only among non–extant examples of the architecture of wooden synagogues in the former Commonwealth. On–the–spot investigations, albeit for the time limited to select objects in historical Greater Poland, have demonstrated that churches with a double carrying roof construction are not as exceptional as it might be assumed upon the basis of pertinent literature. Solutions similar to the “G¹sawa” model have been discovered in both seventeenth– and eighteenth– century churches. At the present stage it is still difficult to draw concrete conclusions concerning the origin and evolution of wooden churches with a double, frame–skeletal wall construction, which calls for further studies. Today, the most important is the very fact that this type of construction has been classified in sacral architecture of the Christian cultural range.