The great technological and typological variability identified among the Middle Palaeolithic (MP) assemblages previously assigned to the Zagros Mousterian in the Zagros suggests that this industry is not a homogeneous cultural unit. The archaeological record from the Caucasus and Armenian highlands contributes important data to understand the variability of the Zagros Mousterian. The authors show that the long stratigraphic sequences of the caves of Taglar in the Lesser Caucasus and Yerevan-1 in the Armenian highlands provide a line of development (the ‘Yerevan–Taglar tradition’) of the Zagros Mousterian variant in this region at least from 60/55 to 40 kya. The earliest manifestations of the Zagros Mousterian in the regions may be dated to the early MIS 5 or earlier. The MP assemblages from the cave of Saradj-Chuko and two other MP sites in the Terek river basin represent the northern Caucasian variant of the Zagros Mousterian, which existed in the region from MIS 5 to MIS 3. The remains of Neanderthals associated with the Zagros Mousterian assemblages in the Zagros and Caucasus clearly indicate that the makers of this cultural tradition were Neanderthals.