The Visean-Serpukhovian boundary beds are studied in the valley of Alabaital Creek (Dombar Hills, Aktyubinskaya Region). Ammonoids, conodonts, and ostracodes are collected from the same levels. A section spanning the boundary between the Hypergoniatites-Ferganoceras and Uralopronorites-Cravenoceras Genozones is described and measured. This section displays the level of the first appearance of the conodont Lochriea ziegleri, currently considered to be the best ?andidate for the V-S boundary marker, being below the base of the Uralopronorites-Cravenoceras Genozone. The lithology of the Visean-Serpukhovian boundary beds is described, and their correlation is proposed.