The process of iron production in the territory of Poland during the Roman Period has so far been discussed in detail only in relation to the Przeworsk Culture. In the case of the Wielbark Culture, this subject has not been thoroughly analyzed. This state of affairs is caused in part by a small number of fully researched settlements of the Wielbark Culture and the fact that the Wielbark people did not usually deposit iron objects in their graves. Ryszard Wołągiewicz (1974, p. 129–130) showed that the ratio of iron to bronze objects registered in the graves of this culture is 1:30. Newer studies indicate that the ratio can vary significantly from site to site. For example, at the cemetery in Ulkowy site 1, Gdańsk County, approximately every twelfth item was made entirely of iron. In Grzybnica, Koszalin County, it was every third item. In Pruszcz Gdanski site 10, Gdańsk County, every sixteenth artefact was made of iron, yet in Weklice, Elbląg County, it was every ninth one (M. Woińska 2015, p. 177–178). The oldest grave assemblages containing iron artefacts are dated to the phase B1. They come mainly from the cemeteries previously used by the people of the Oksywie Culture. Therefore, there are sometimes difficulties in determining their cultural affiliation. The same applies to settlements which were first used by the people of the Oksywie or Przeworsk Culture and then by the population of the Wielbark Culture. In spite of this, features associated with the iron production process are identified at the settlements associated unequivocally with the Wielbark Culture (Fig. 2, Table 2). These include slag-pit furnaces, forge hearths, features related to the initial preparation of bog ore, and – indirectly – lime and charcoal kilns (Fig. 3–5). Such features were discovered in the greatest number at the settlement at Rogowo site 23, where 441 slag-pit furnaces were identified. Some of them came in pairs forming larger disordered clusters (E. Bokiniec 2016a, p. 16). From a few to a dozen or so slag-pit furnaces were discovered at other settlements discussed herein (Gotelp site 14, Kakulin, Klonówka site 7/54, Leśno site 10, Łosino site 15, Poznań-Sołacz, Stanisławie site 37, Stroszki site 1, Tarnowo Pałuckie site 13, Widzino site 8). These furnaces were not organized, and the iron produced there was probably used for local needs only. Furthemore, concentrations of features defined as forges have been identified at the settlements in Stroszki and Poznań-Sołacz. It is worth noting that iron objects also appear at the settlements of the Wielbark Culture (Fig. 6). The largest number (over 70) was registered in Lipianki site 3. They comprised brooches – A.IV.74 (Fig. 7:1), A.V series 8, A.VI.158, A.VI.161–162, A.VI.170 (Fig. 7:2), belt buckles, casket fittings, spurs (Fig. 7:3) as well as awls, needles and knives (A. Strobin 2015, p. 125–135).