The gmina covers an area of 227.3 square kilometres (87.8 sq mi).

It is located approximately: The region has a continental climate which is characterized by high temperatures during summer and long and frosty winters .

The following villages are contained within the gmina: Bronka, Brzeźnica, Burchaty, Chojewo, Chojewo-Kolonia, Chrościanka, Dębowo, Domanowo, Ferma, Glinnik, Holonki, Jarmarkowszczyzna, Kadłubówka, Kalnica, Kalnowiec, Kiersnowo, Kiersnówek, Kiewłaki, Klichy, Konotopa, Koszewo, Lubieszcze, Majerowizna, Markowo, Mień, Nowosady, Oleksin, Olędy, Olędzkie, Olszewek, Olszewo, Otapy, Pace, Pasieka, Patoki, Pietraszki, Płonowo, Poletyły, Popławy, Pruszanka Stara, Pruszanka-Baranki, Puchały Nowe, Puchały Stare, Spieszyn, Szmurły, Ściony, Świrydy, Widźgowo, Załuskie Koronne, Załuskie Kościelne, Zanie.

Gmina Brańsk is bordered by the town of Brańsk and the Gminy of Bielsk Podlaski, Boćki, Dziadkowice, Grodzisk, Klukowo, Nowe Piekuty, Poświętne, Rudka, Szepietowo and Wyszki.

Gmina Brańsk is at the intersection of a National Road and a Voivodeship Road: Regular bus service is provided in the town of Brańsk by Państwowa Komunikacja Samochodowa (State Car Communication, PKS) via PKS Bielsk Podlaskie, PKS Białystok and PKS Siemiatycze The closest passenger train service is provided by Polskie Koleje Państwowe (Polish State Railways, PKP) SA from the following stations: