Volcanic events were frequent during formation of the Pannonian Basin. Repeated explosive eruptions of silicic magmas produced volcaniclastic deposits that covered a large area, although presently most of them are overlain by younger deposits. Mountains surrounding Pannonian Basin host well exposed outcrops of the Early and Middle Miocene deposits with volcaniclastic horizons, which provide detailed evidence of volcanic events. At Mt. Požeška gora, the thickest primary volcaniclastic layer was analyzed using a ”multi-proxy“ approach (sedimentology, high-precision zircon geochronology, 40Ar/39Ar radiometric dating, volcanic glass geochemistry) and dated to ~15.3 Ma [1]. Volcaniclastic layers potentially contemporaneous with Požeška gora ~15.3 Ma horizon were recorded regionally, from the Vienna Basin [2] to the North Alpine Foreland Basin [3] as well as Dinaride Lake System [4]. In this research, we analyzed three volcaniclastic layers variously distanced from the Požeška gora site to determine the wide spread ~15.3 Ma volcanic event. Our study shows that using data from a single glass shard geochemistry and zircon geochronology enables correlation of Požeška gora volcaniclastic horizon with Kuchyňa (Vienna Basin), Lučani (Sinj Basin) and Čučerje sites (Mt. Medvednica). These sites are 100–300 km away from Mt. Požeška gora locality. This volcanic event can be used as a marker horizon for the Neogene stratigraphy in the wider area of the Pannonian Basin.