Abstract— Precise radiometric age determination of the Kaalijärv meteorite craters on the island of Saaremaa in Estonia have so far proved inconclusive. Here we present trace element analyses of peat cores taken several kilometers away from the Kaalijärv craters that reveal a distinct Ir-enriched layer produced by the meteorite impact. By radiocarbon dating the peat cores, we have determined for the first time the precise age of the impact that generated the Kaalijärv craters. The calibrated date of the impact is 400–370 B.C. at ± 1σ.