Site no. 3 at Słupno, distr. Wołomin, was discovered during a surface survey during early 1990s (Fig. 1). It yielded four featureless fragments of prehistoric pottery, two of them evidently burnt, and a slightly damaged bronze fibula (Fig. 2a) with a high catchplate and an upper cord, a type defined as “Sarmatian”. It is commonly understood that similar forms emerged in the Danubian region and later spread to the north. They are dated to the second half of the 2nd and onset of 3rd century AD; in the northern reaches of Central European Barbaricum they linger a little longer, until the end of the first half of 3rd century (phases B2/C1–C1b). At present a few score fibulae of the described form are recorded in Poland, mostly on the territory occupied by Przeworsk settlement with a smaller number recorded in sites attributed to Wielbark Culture. The fibula from Słupno is one of only two specimens of this type discovered in the area of Mazowsze on the right-hand bank of the Vistula River and in Podlasie. The second fibula comes from grave 12/61 in the cemetery at Goździk 1, distr. Garwolin (Fig. 2b). Neither fibula can be dated reliably from its context, so we have to base on the chronology of similar forms recorded outside the region and confine them both to phase B2/C1–C1a. At this time in right-bank Mazowsze there was a major change in the culture outlook, associated with a southward migration of Gothic tribes. The findings of recent decades confirm a partial coexistence of local Przeworsk communities with the bearers of Wielbark Culture moving into the area from the north. In this situation it is legitimate to address the question of culture attribution of fibulae from Goździk and Słupno. While we can attribute the fibula from Goździk relatively soundly to Wielbark Culture, determining the culture attribution of the surface find from Słupno is more problematic. The site lies within a settlement concentration found to the left of the lower reaches of the Narew River. Archaeological material discovered in the nearby grave-fields (e.g. Łajski, distr. Legionowo, Załubice Stare, distr. Wołomin) testifies to a continued presence of Przeworsk communities until the onset of the Late Roman Period. hus, we cannot hope to establish the culture attribution of the fibula from Słupno conclusively. Nevertheless the fact group VII fibulae with a high catchplate are absent from the archaeological record in the Eastern zone of Przeworsk Culture suggests that the specimen may have a Wielbark provenance.