Castor is an important industrial non-edible oilseed crop. Castor seed contain 45-47 % non-edible oil, which is used as domestic, medicinal and industrial purposes. Castor oil is used as a lubricant in all moving parts of the machinery and particularly high speed engines and aero planes. Hydrogenated castor oil is used in polishes, varnishes, transparent paper, linoleum, plasticizers, ointments, waxes, printing ink, cosmetics, hairdressing, soaps etc. In dyeing industries and disinfectants, it is used for the preparation of Turkey red". Castor oil is also used as purgative. It is used in many veterinary uses. It is also used for medicinal and lighting purposes. It is use externally as an emollient and also used as soothing medium when dropped into the eyes of animals after removal of foreign bodies. Oil received from small seeded variety is of very good quality and specially used as a medicine, while oil received from bold seeded variety is used for lightening and lubrication etc.

Because of its deep root system, drought hardiness and quick growth, it finds a place of prestige in the cropping systems of dryland agriculture in semi-arid zones of India. The castor cake is valuable manure for field crops but due to the presence of poison "Ricin", it is not feed to the cattle. It is useful as a trap crop because root contain "ricin" (poisonous alkaloids) which kills nematodes entered into roots. It is used as windbreak crop for sugarcane, papaya and banana crops. In eri silk-producing areas, leaves are fed to eri worms. The plant stalks are used for fuel purpose or as that ching material or for preparing paper pulp.

Castor plant is also grown on the border of the nursery for natural insect control. The prodenia (leaf eating cater pillar) may lay the eggs on the lower side of the leaves of the castor, which can be destroyed by picking the leaves, and buried into the soil. This crop is also helpful as a trap crop as roots of plants trap the nematods.

Dry leaves of castor contain 24 % crude protein along with "ricin alkaloid which is poisonous but green mature leaves can be fed to the cattle with proper care i.e after washing them into the water.

Castor seed and castor cake are highly poisonous to man and animal because it contains a toxic alkaloid ricinine and ricin. But the castor cake is a good source of organic manure as it contains nitrogen 4.5 %, P2O5 1.75 % and K2O 1.5 % and also control white ants and nematodes.