As a well stimulation technique, hydraulic fracturing has a wide range of applications, including the development of unconventional resources, production enhancement in low- and moderate-permeability reservoirs, bypassing near wellbore damage in high-permeability reservoirs, reducing sand production in loosely consolidated or unconsolidated sandstone reservoirs, and connecting the natural fractures in a formation to the wellbore. Hydraulic fracturing is a process in which fluid is pumped through the wellbore into the targeted formation at pressures high enough to break the rock and create a fracture. A clean fluid is typically pumped initially to allow the fracture to initiate and propagate. Once the desired fracture dimensions are achieved, the pumping is switched from the clean fluid to a mixture of fluid and proppant. Upon the completion of the process, the fluid inside the fracture continues leaking off into the formation until the fracture closes on proppant. The goal of hydraulic fracturing is to create a conductive path from the wellbore extended deep into the reservoir. This chapter presents a detailed description of hydraulic fracturing treatments covering basic rock mechanics, overview of hydraulic fracture geometry, fracture models, fracturing pressure analysis, fracturing materials and equipment, fractured well productivity, fracturing treatment design, frac-pack treatments, fracturing horizontal wells, and fracturing treatment evaluation.