In Croatia, Šešum families are mainly Serbs, less frequently Croats (also from Middle Bosnia ). In the past century, relatively most of Croatian residents bearing this family name were born in Middle Bosnia (Kupres area) and in Nova Gradiska.
About 10 people with faimily name Šešum live in Croatia today, in 6 households. There were 0 of them in the middle of the past century, and their number multiplied. They are located in four Croatian cities only: in Osijek (<10), Pula (<5), Rovinj (<5), and in Beli Manastir (<5).