This paper is a review of Resorcinol bis(diphenyl phosphate) (RDP), a non‐halogen aromatic oligomeric phosphate flame‐retardant and flow modifier. Its high thermal stability and low volatility, compared with the triaryl phosphates, make it ideal for use in applications where high processing temperatures are requuired. Thermogravimetric data showing the effects of RDP on modified PPO and polycarbonate/ABS blends are presented. Current and potential end uses in thermoplastic resins and polyurethanes are discussed.