It is in the foothills of the Serra da Mantiqueira south of the state capital Belo Horizonte at an elevation of 1,136 meters, making it one of the ten highest cities in Brazil. Located on the important BR-040 highway (also called Rodovia JK), which links Brasília to Rio de Janeiro, it is 165 km from the state capital and 97 km from Juiz de Fora.
Barbacena has a humid tropical climate with cool summers due to the elevation. Summer averages are 24 °C and winter averages 13 °C. The cool climate and abundant rainfall have made Barbacena a center for flower production - the city is the biggest producer of flowers in Minas Gerais, and is nicknamed "City of Roses". Cattle raising and the dairy industry are quite developed and the city is a big producer of milk products; there are also several small textile factories.
In the 19th century, Barbacena was a principal distribution center for the mining districts of Minas Gerais, but this distinction was lost when the railways were extended beyond that point.
Barbacena is also the home of the Preparatory School of Air Cadets (the sixteenth best high school of the country, which belongs to the Brazilian Air Force) and of a Medical School, Faculdade de Medicina de Barbacena (Faculty of Medicine of Barbacena).
Barbacena was the birthplace of the human rights activist and lawyer Heráclito Fontoura Sobral Pinto.
Barbacena was a station on the Estrada de Ferro Oeste de Minas, a narrow gauge railway.