The Zagorje-Trbovlje subdialect is influenced by both Styrian and Upper Carniolan features, and it is generally closer to Standard Slovene because of immigration to this area.

The Sevnica-Krško subdialect extends north up to Sopota, Čimerno, Radeče, Žirovnica, Podgorica, and Podgorje ob Sevnični.

Notable settlements include Sava, Litija, Polšnik, Zagorje ob Savi, Trbovlje, Hrastnik, and Zidani Most in the Zagorje-Trbovlje subdialect, Rimske Toplice and Laško in the Laško subdialect, and Radeče, Loka pri Zidanem Mostu, Dolenji Boštanj, Sevnica, Blanca, Brestanica, Senovo, Krško, Studenec, Leskovec pri Krškem, Raka, Cerklje ob Krki, Podbočje, and Kostanjevica ob Krki in the Sevnica-Krško subdialect.

The dialect is in the late stages of losing length distinctions because all short vowels tend to lengthen.

It has also undergone the *məglȁ → *mə̀gla accent shift and, as opposed to the Eastern Lower Carniolan subdialect, it is consistent.

Short stressed *ȉ and *ȕ lengthened into iː (or sometimes eː) and uː in the east, but turned into *ə in the west.

The Zagorje-Trbovlje subdialect also has the syllabic sonorants l̥, m̥, n̥, r̥, which formed after the neighboring unstressed vowels disappeared.

Final non-sonorants became devoiced, and the cluster šč simplified into š, except at the beginning of a word in the Zagorje-Trbovlje subdialect.

Verbs do not often follow the -a-ti -je-m paradigm common for Styrian dialects (e.g., umivati → umivljem 'wash').