It lies between Malda and Siliguri. On the west are Katihar, Purnea and Kishanganj districts of Bihar. On the east are Dinajpur and Thakurgaon districts of Bangladesh and Dakshin Dinajpur in India.
The dialects and languages spoken here include the Bengali, Urdu, Hindi, Rajbansi, Santali, Mundari and Kurukh. The Islampur sub division was earlier in Purnea. The Raiganj sub division was part of undivided Dinajpur. Both were part of the erstwhile West Dinajpur for a quarter of a century.
The 2001 Census population of the district was 2.4 million people. The birth rate in Islampur sub division was estimated to be around 35/ 1000 population in 2001. The birth rate in Raiganj sub division was estimated to be around 30/ 1000 population in rural areas.
