After many unsuccessful attempts to establish its linguistic affinity, Sumerian is nowadays widely considered a language isolate without any known relatives. However, a systematic comparison of its vocabulary and morphology with all the major Eurasiatic language families establishes beyond doubt that Sumerian belongs to the Uralic language family and is distantly related also to many other languages currently spoken in Europe, Western Asia and North Africa. This etymological dictionary brings together the lexical evidence associating Sumerian with the Uralic family, along with comparative data from five other language families (Indo-European, Altaic, Kartvelian, Elamite-Dravidian and Afro-Asiatic). Part 1 presents Uralic etymologies for 3030 Sumerian words and lexical morphemes accounting for about two-thirds of the Sumerian core vocabulary, as well as an introduction assessing the linguistic affinity of Sumerian. Part 2 contains a semantic analysis of the Sumerian and Uralic lexical material, indexes to Part 1, and an introduction discussing the origins and arrival of Sumerians in Mesopotamia on the basis of epigraphic, linguistic, archaeological and physical anthropological evidence. The relevant data have never before been put together, let alone analyzed, and they open revolutionary new perspectives to the origins and prehistory of the Sumerians and the Uralic and Indo-European language families.