The sources of archaeological obsidian in central and eastern Europe are briefly described, and analyses of 48 samples from ten of these sources in northeast Hungary and southeast Slovakia are reported. Instrumental neutron activation analysis was used to determine 16 trace elements and two major elements. Principal components analysis supported by discriminant analysis showed seven analytical groups in these data. A total of 270 pieces of archaeological obsidian was assigned by discriminant analysis to three of the Carpathian source groups defined, the remaining four source groups not being represented in the archaeological record. The three source groups used are: 1)Szöllöske and Malá Torona in Slovakia (designated group Carpathian 1); 2) Csepegö Forrás, Tolcsva area, Olaszliszka and Erdöbénye in Hungary (Carpathian 2a); and 3) Erdöbénye (Carpathian 2b). Carpathian 2a and 2b type obsidians are both found at the re-deposited source of Erdöbénye. Carpathian obsidian was used most widely in Hungary, Slovakia, and Romania; and also reached south to the Danube in Yugoslavia, west to Moravia, Austria, and to the Adriatic near Trieste, and north to Poland. Carpathian 2a obsidian was used in the Aurignacian period, Carpathian 1 in the Gravettian and Mesolithic, and Carpathian 1, 2a and 2b in the Neolithic, when Carpathian 1 predominated and obsidian use was at its most intensive. Only Carpathian 1 type has been identified in the Copper and Bronze Ages. There is no evidence at present for any overlap between the Carpathian obsidian distribution and the distributions of the Near Eastern or Aegean sources, but there is an overlap with Mediterranean obsidian at the Neolithic site of Grotta Tartaruga in northeast Italy where Liparian and Carpathian 1 materials were identified. The distribution of obsidian from the Carpathian sources is considered in terms of linear supply routes. Based on limited available evidence the supply zone is significantly smaller and the rate of fall-off with distance slightly lower than that reported for Near Eastern obsidians. See also AATA Vol. 15, Abstract No. 241, PARIS No. 86903 for related study.