Bihar, a state of India, currently has 38 administrative districts, 101 subdivisions (अनुमंडल) and 534 CD blocks.
A district of an Indian state is an administrative geographical unit, headed by a district magistrate or a deputy commissioner, an officer belonging to the Indian Administrative Service. The district magistrate or the deputy commissioner is assisted by a number of officials belonging to different wings of the administrative services of the state.
A superintendent of police, an officer belonging to Indian Police Service, is entrusted with the responsibility of maintaining law and order and related issues.
3 to 6 districts are comprised to form a division (प्रमंडल). Each district is divided into sub-divisions (अनुमंडल), which are further sub-divided into CD blocks (प्रखण्ड).

Detailed List
| 
 | Code | District | District Headquarters | C.D. Blocks | Population (2011) | Area (km²) | Density (/km²) (2011) | Map | 
|---|---|---|---|---|---|---|---|---|
| 1 | AR | Araria | Araria | 
 | 2,811,569 | 2,829 | 751 |  | 
| 2 | AW | Arwal | Arwal | 
 | 699,000 | 637 | 918 |  | 
| 3 | AU | Aurangabad | Aurangabad | 
 | 2,540,073 | 3,303 | 607 |  | 
| 4 | BA | Banka | Banka | 
 | 2,034,763 | 3,018 | 533 |  | 
| 5 | BE | Begusarai | Begusarai | 2,970,541 | 1,917 | 1,222 |  | |
| 6 | BG | Bhagalpur | Bhagalpur | 
 | 3,037,766 | 2,569 | 946 |  | 
| 7 | BJ | Bhojpur | Arrah | 2,728,407 | 2,473 | 903 |  | |
| 8 | BU | Buxar | Buxar | 
 | 1,706,352 | 1,624 | 864 |  | 
| 9 | DA | Darbhanga | Darbhanga | 
 | 3,937,385 | 2,278 | 1,442 |  | 
| 10 | EC | East Champaran | Motihari | 5,099,371 | 3,969 | 991 |  | |
| 11 | GA | Gaya | Gaya | 
 | 4,391,418 | 4,978 | 696 |  | 
| 12 | GO | Gopalganj | Gopalganj | 
 | 2,562,012 | 2,033 | 1,057 |  | 
| 13 | JA | Jamui | Jamui | 1,760,405 | 3,099 | 451 |  | |
| 14 | JE | Jehanabad | Jehanabad | 1,125,313 | 1,569 | 963 |  | |
| 15 | KH | Khagaria | Khagaria | 1,666,886 | 1,486 | 859 |  | |
| 16 | KI | Kishanganj | Kishanganj | 
 | 1,690,400 | 1,884 | 687 |  | 
| 17 | KM | Kaimur | Bhabua | 1,626,384 | 3,363 | 382 |  | |
| 18 | KT | Katihar | Katihar | 3,071,029 | 3,056 | 782 |  | |
| 19 | LA | Lakhisarai | Lakhisarai | 1,000,912 | 1,229 | 652 |  | |
| 20 | MB | Madhubani | Madhubani | 4,487,379 | 3,501 | 1,020 |  | |
| 21 | MG | Munger | Munger | 1,367,765 | 1,419 | 800 |  | |
| 22 | MP | Madhepura | Madhepura | 2,001,762 | 1,787 | 853 |  | |
| 23 | MZ | Muzaffarpur | Muzaffarpur | 4,801,062 | 3,173 | 1,180 |  | |
| 24 | NL | Nalanda | Bihar Sharif | 2,877,653 | 2,354 | 1,006 |  | |
| 25 | NW | Nawada | Nawada | 
 | 2,219,146 | 2,492 | 726 |  | 
| 26 | PA | Patna | Patna | 
 | 5,838,465 | 3,202 | 1,471 |  | 
| 27 | PU | Purnia | Purnia | 
 | 3,264,619 | 3,228 | 787 |  | 
| 28 | RO | Rohtas | Sasaram | 2,959,918 | 3,850 | 636 |  | |
| 29 | SH | Saharsa | Saharsa | 1,900,661 | 1,702 | 885 |  | |
| 30 | SM | Samastipur | Samastipur | 
 | 4,261,566 | 2,905 | 1,175 |  | 
| 31 | SO | Sheohar | Sheohar | 656,246 | 349 | 1,880 |  | |
| 32 | SP | Sheikhpura | Sheikhpura | 634,927 | 689 | 762 |  | |
| 33 | SR | Saran | Chhapra | 3,951,862 | 2,641 | 1,231 |  | |
| 34 | ST | Sitamarhi | Dumra, Sitamarhi | 3,423,574 | 2,199 | 1,214 |  | |
| 35 | SU | Supaul | Supaul | 2,229,076 | 2,410 | 724 |  | |
| 36 | SW | Siwan | Siwan | 3,330,464 | 2,219 | 1,221 |  | |
| 37 | VA | Vaishali | Hajipur | 3,495,021 | 2,036 | 1,332 |  | |
| 38 | WC | West Champaran | Bettiah | 3,935,042 | 5,229 | 582 |  | |
See also
| Divisions | 9 | 
|---|---|
| Districts | 38 | 
| Subdivisions | 109 | 
| Cities and towns | 207 | 
| Blocks | 534 | 
| Villages | 45,103 | 
| Panchayats | 8,406 | 
| Police Districts | 43 | 
| Police Stations | 853 | 

