As per 1991 census, the total population of Purnia district is 18,78,885 of which 9,87,241 are male and 8,91,644 are female. The district is divided into 4 sub divisions, 14 Blocks, 251 Gram Panchayats, and 1296 villages. The river Kosi and Mahananda and their tributaries irrigate different parts of the district.
Since agriculture is the principal occupation of the people of Purnia. Crops grown in this region are paddy, Jute, Wheat, Maize, Moong, Masoor, Mustard linseed, Sugar cane and Potato. Jute is the major cash crop of Purnia district. Fruit plants like coconut, Banana, Mango, Guava, Lemon, Jack Fruit, Pineapple and banana are also grown here. Rearing of livestock like goat, cow and pig is very popular in Purnia. It produces the maximum number of poultry and eggs in Bihar. The Sugar mill at Banmankhi and 716 other small-scale industries provide employment to the people of Purnia.
Purnia district can be accessed by using road and rail services. The nearest railway station of the district is Katihar, and Purnia is also connected with National Highway No. - 31 to the various states of India.
Popular tourist destinations of Purnia district are:
- Kajha Kothi
- Kali Bari Mandir
- Temple of Goddess Puran Devi
- Temple of Mata Asthan, Chuna Pur
- Temple of Goddess Radha Krishna, Madhubani
- Millia Fakhuruddin Ali Ahmed Teachers Training College
- M L Arya College
- Surya N Singh Yadav College
- B N C College
Bihar Assembly Election 2010