The chapter deals with products and by-products of petroleum, their uses, their refinement, and effects on the environment. Petroleum in its crude form has not much value, but when refined yields a range of products and by-products, which the humankind cannot do without. This chapter deals in detail the different stages involved in the fractional distillation of petrol to obtain each of its products and refining of each of them. The products have been classified here, based on the state they exist in, namely solid, semi-solid, liquid, and gaseous matter. The products and by-products discussed include liquefied petroleum, natural gas, shale gas, refinery gas, naphtha, gasoline, solvents, kerosene, diesel, fuel oil, lubricating oil, white oil, insecticides, grease, wax, asphalt, coke, etc.