Benac focused his research on prehistory within the Western Balkans, and undertook numerous systematic archaeological excavations on sites including Arnautovići (Visoko), Crvena Stijena (Montenegro), Hrustovača in Hrustovo (Sanski Most), Obre I and II (Kakanj), Zecovi (Prijedor), Zelena Pećina in Blagaj (Mostar) and others.