In 2018, a bronze brooch dating to the Roman Period was handed over to the County Monuments Preservation Department of the Poznań County Office. The artefact was discovered accidentally in a forest area within the grounds of the village of Wierzonka, in the commune of Swarzędz, Poznań County (Fig. 1). The brooch comes from as of yet unknown, unidentified archaeological site. The characteristic feature of the brooch (Fig. 2:a–c) is a circular disc with two smaller, round, bowl-shaped protrusions at its perimeter; a third such protrusion could have originally been located on the upper part of the disc. A raised circular knob (tutulus) cast together with the fibula body is located at the center of the disc. The flat tip of the knob is decorated with two round, enameled fields – a yellow field on the inside, and a blue and navy one on the outside. Both protrusions could have also been originally enameled. What constitutes a special element of the Wie¬rzonka brooch is an openwork triangle with circular, bowl-shaped protrusions at each corner, probably also initially enameled. The brooch has a hinged construction, typical of provincial Roman fibulae. Preserved length of the brooch is 3.9 cm, full height approx. 1.6 cm, disc diameter 2.0 cm. The brooch corresponds to type I 52 after K. Exner (1941) or 7.13 after E. Riha (1994) and also to types IV/2/1/1 and IV/2/1/3 in the classification of enameled fibulae from Panonia (A. Vaday 2003). Close analogies to the brooch from Wierzonka can be found in the Rhine and Danube provinces of the Roman Empire (Fig. 3). They are dated to the 2nd and 3rd century AD, which does not allow for an unequivocal identification of the Wierzonka brooch with either the Przeworsk or Wielbark Cultures, more so since this fibula is a unique specimen in the territory of Poland.