Sullah and Itna upazila on the northwest, Baniachang upazila on the east, Mithamain upazila on the south.

Ajmiriganj thana was turned into an upazila in 1983. It consists of five unions, 68 mouzas and 79 villages.

Ajmiriganj Upazila is located in Habiganj District. Upazilla(s)/Thana(s) in Habiganj are Ajmiriganj Upazila, Baniachang Upazila, Bahubal Upazila, Chunarughat Upazila, Habiganj Sadar Upazila, Lakhai Upazila, Madhabpur Upazila, Nabiganj Upazila.