A group of unpublished finds now in keeping of the State Archaeological Museum in Warsaw was discovered at Grodzisk, Węgrów County, some 80 km east of Warsaw (Fig. 1). It falls into two groups – a pottery assemblage collected in 1937 by Anoni Brzezik, inhabitant of Grodzisk, and finds from a surface survey of site 4 at Grodzisk made in 2009 by Mateusz Bogucki. The artefacts from site 4 fall into two groups. The first group is attributable to Younger Pre-Roman Period and the Roman Period occupation, with individual finds dated to the period lasting form the mature phase A1, possibly, onset of phase A2 until stadium C2b. The second group are artefacts from late 6th and early 7th century associated with the earliest phase of Slav settlement in Mazovia. The assemblage of finds with the earlier dating consists of the following: a copper alloy neckring with cylindrical terminals (Fig. 3:1), an iron brooch with a crest on the head decorated with impressed silver foil (Fig. 3:2), a denarius of Hadrian (RIC 141b) (Fig. 3:3), a copper alloy brooch, type Almgren 168 (Fig. 3:4) and a fragment of a bronze spring from a brooch (Fig. 3:5). Given their chronology these artefacts may be attributed to two culture units recorded in the Liwiec River valley: Przeworsk culture and Wielbark culture. The neckring of a form typical for Jastorf culture would be one more find of this culture recovered in a zone of the earliest phase of Przeworsk culture settlement. The character of finds from site 4 suggests that they originate from a bi-cultural, long-lived cemetery. However, because of its partial investigation it is unclear whether or not the cemetery was used without a break, like many cemeteries known from the eastern zone of the Przeworsk culture. The younger group of artefacts includes a fragment of a copper alloy radiate-headed brooch (Fig. 3:6) with a reduced ornamentation and a fragment of an openwork object, also in copper alloy (Fig. 3:7), possibly a belt mount of a type encountered during the late Migration Period on Balt territory. Chronologically, both these finds may be safely attributed to the earliest period of Slav settlement in eastern Poland, although it is also possible that their presence in our region is the result of exchange with Balt peoples. Another find from site 4 is a blue glass bead, type bisier (Fig. 3:8). The rather broad chronology of these beads precludes a more conclusive dating of this specimen. It is possible nevertheless that it has a connection to the nearby hill-fort (cf. Fig. 1) which has its first phase dated to the 10th century. The other segment of the assemblage from Grodzisk is a group of more than 170 pottery fragments collected in 1937 (Fig. 4). Their exact find-site is unknown – presumably, they were discovered in the garden of the farm of A. Brzezik, which was found within site 43C. The heavily burnt condition of most of these pottery fragments prevented reconstruction of a complete vessel. Where a partial reconstruction was possible the vessels had a form recorded in the Przeworsk culture during phases B2 and B2/C1 (Fig. 4). The preservation of the pottery fragments establishes their provenance from a funerary context. Consequently, we have to assume the presence at Grodzisk of two cemeteries (Przeworsk, or Przeworsk-Wielbark) separated by a small distance (c. 700 m). More finds from the same period have been recovered at Grodzisk. The remains of a Przeworsk culture settlement dated to phases A2–B1) were identified during the investigation of the interior of the early medieval hill-fort. From a farm lying in an area recorded as site 43C adjacent to the former “garden of A. Brzezik” comes a find of a copper alloy brooch, type Almgren 128, and a small quantity of pottery attributed to the Przeworsk culture. This could mean that, similarly as the cemetery in site 44, the cemetery in site 43C was used both by the Przeworsk and the Wielbark people.