Eoalpine very low- to low-grade metamorphism related to Cretaceous orogenesis has been investigated in the Slavonian Mts, Croatia. Samples belonging to the Psunj metamorphic complex (PMC), the Radlovac metamorphic complex (RMC) and Permian-Triassic and Triassic sedimentary sequences (PTSS) were studied. The Kübler and Arkai indices of all the analysed samples indicate high-anchizonal to epizonal metamorphism. The degree of Eoalpine metamorphism tends to be constant in all samples implying that the different complexes passed through and recorded the same event. Measurements of illite-white K-mica b₀-parameter of the RMC samples imply transitional low- to medium-pressure character of the metamorphism. These data together with K-Ar ages (~100–80 Ma) measured on illite-white K-mica rich <2 mm grain-size fractions point to Late Cretaceous very low- to low-grade regional metamorphism presumably related to the main nappe-forming compressional events in the Pannonian Basin and the Carpathians. The P-T-t (pressure-temperature-time) evolution of the studied area is in good agreement with similar scenarios in the surrounding areas of Tisia, but also in Eastern Alps, Carpathians and Pannonian Basin (ALCAPA).