Parshuram upazila on the north, Mirsharai upazila on the south, Indian State of Tripura on the east, Feni Sadar upazila on the west.

Chhagalnaiya thana, now an upazila was established in 1872. The upazila consists of 6 union parishads, 54 mouzas and 63 villages.

Chhagalnaiya Upazila is located in Feni District. Upazilla(s)/Thana(s) in Feni are Chhagalnaiya Upazila, Daganbhuiyan Upazila, Feni Sadar Upazila, Parshuram Upazila, Phulgazi Upazila, Sonagazi Upazila.

Shiluar Shil, Shuvapur Bridge, Banchpara Zamindar Bari and Sat Mandir (seven temple), remnants of the capital of Shamser Gazi, Kayara Dighi.