In 1926, Bulgaria bought the first narrow-gauge passenger cars, which immediately took over services on the newly built line from Saranbey to Ladzhene. By the time of the opening of this section of the future railway Tatar Pazardzhik - Nevrokop, the Rhodope Narrow Gauge held a total of four cars. They were all third-class, without compartments, and with the typical for that time wooden seats - benches. At both ends of the car there were open plattforms, like terraces. The cars were manufactured at the KOPRIVNICKA VOZOVKA AKC. SPOL. plant.

In 1939, four baggage cars were delivered by the German "Bautzen" company.

Eight further passenger cars werde delivered in 1941. They were similar to the previous ones but they had a separate compartment with soft seats, cushioned in red - second class. They were also produced by "Bautzen". After the abolition of the third class in the Bulgarian State Railways as of 1st June 1956, the second class became first and the third became second.

27 years later, in 1968, the "Andrey Zhdanov" factory in the Bulgarian town of Dryanovo produced new second-class passenger cars for the Septemvri - Dobrinishte narrow-gauge line. After two years of trials and improvements, they were put into operation in 1970. Until 1974, a few more batches of the same cars were produced and delivered. A baggage car and a buffet car were also designed and produced after the same model.

In 2015, the Septemvri - Dobrinishte narrow-gauge possesses 30 passenger cars, 3 baggage cars, which are out of service, and 2 buffet car - crates. Furthermore, the two retro cars of the "Nostalgia" trainset are also kept at station Septemvri.