Both commercially and domestically textiles are used commonly, and they are widely used in the interior of both housing and industrial facilities. The fibers used for making these textiles come from naturally occurring polymers such ascellulose, protein, keratin, etc., or from synthetic polymers- polyamide, polyester, polyacrylonitrile, cellulose acetate, etc. All these fibers are highly flammable and combustible, and pose serious fire hazard in case of fire accident. Statistics says that over 70% of fire deaths in dwelling are caused by textiles. In many cases, to prevent fire and save lives it is needed to give fireproof properties to textiles. Therefore, flame retardant finish is one of the important finishes among the various available functional finishings of textiles. This chapter will discuss the history and importance of flame retardant finish, types of available flame retardant finish. The factors affecting the flammability and the standard test method for testing flame retardancy of textiles also will be discussed. This chapter will also give an insight into the advancement of flame retardant synthetic fibers and environment issues related to flame retardant agents.