In Assam the Planning & Development Department was set up towards the last part of 1944. Initially the Planning and Development Department was made responsible for the Community Development works till the separation of the Department of Community Development. However the Planning and Development Department continued to be responsible for local development works, the Umtru Hydel Project and the administration of overseas scholarship scheme and was also made the administrative Department for social welfare.

After a major re-organisation in 1958 and afterwards the Department was made the Administrative Department for Directorates of Economics & Statistics, Evaluation & Monitoring Division, Plan Co-ordination Division, Manpower Division, Decentralised Planning Division, 20-Point Programme Cell, NEC Cell, Computer Application Division and the P&D Library.

The Planning and Development Department is the core Department so far as the formulation and implementation of the State Plan schemes are concerned and guides the line departments of the State in respect of formulation, implementation and review as well as maintenance/ reporting of records on physical progress and financial achievements. The Department prepares draft Annual Plans and Five Year Plans as per the guidelines of the Planning Commission and as per needs and aspirations of the people. After finalization of the resources likely to be available for the concerned Five Year Plan or Annual Plan, the Department quantifies the flow of funds for various sub-plans viz., Hill Plan, Tribal Sub-plan (TSP) , Scheduled Caste Component Plan (SCCP) and Bodo Territorial Council (BTC) Plan. From the balance, the Department distributes sector wise Five Year Plan and Annual plan outlays for preparation of plan budget under General Areas.