The Dzongkhag has total area of 1877.37 sq km sharing border with Indian state of Assam in the south and Arunachal Pradesh in the east. Dzongkhag shares national borders with Pemagatshel Dzongkhag in the west, and with Trashigang Dzongkhag in the north.
There are two Drungkhags viz Samdrupcholing and Jomotshangkha.
Samdrupcholing Drungkhag comprises of four Gewogs namely Marthalla, Pemathang, Phuntshothang and Samrang. Jomotshankha Drungkhag has three Gewogs namely Lauri, Serthi and Langchenphu. Rest of the Gewogs namely Gomdar, Wangphu, Orong and Dewathang are administered by the Dzongkhag.
The largest gewog in terms of area is Marthsalla with 18% while Samrang, Gomdar and Wangphu are the smallest with 3% each of the total area.

The population of the Dzongkhag is 33,889, of which17444 are male and 16445 are female. The sex ratio is 105 male per 100 female. 12467 people from this Dzongkhag are out migrants and have immigrants of 2935 people.
The population is fairly distributed amongst the gewog except in Samrang with only 1% of the total population.
More than half of the Dzongkhag population (18420) is in between the age group of 15 years-44 years and half of the population (14044) are less than the age of 15 years. The Dzongkhag has a minimum (7000) population in the age group of 45 years and above.

The Dzongkhag is located in the sub-tropical climatic zone with fertile plain land mostly in Pemathang, Phuntshothang, Langchenphu and Samrang Gewogs.
Altitude in the Dzongkhag ranges from 200 meters to 3600 meters where major portion of the land falls within the altitude ranging from 600 meters to 1200 meters above sea level.
The Dzongkhag experiences highest temperature of 36 degree centigrade and minimum temperature of 14 degree centigrade.
Dzongkhag receives average annual rainfall of 5309.4 millimeters recorded at Aerong. The highest rainfalls at two stations receive in the months of June and July measuring 916.4 millimeters to 1887.2 millimeters.