Phosphonated polymers with a well-defined molecular weight, composition and architecture have been prepared via ring opening metathesis polymerization (ROMP) of phosphonated and non-phosphonated norbornene imides at room temperature for the first time. ROMP was proven to be living and versatile. This enabled preparation of a broad range of phosphonated homopolymers, statistical copolymers, AB diblock as well as ABA and BAB triblock copolymers based on poly(norbornene imide)s with low poly-dispersity (1.09-1.32). Complete hydrolysis of phosphonated poly(norbornene imide)s under mild conditions yielded the phosphonic acid derivatives. Thermogravimetric analysis indicated high thermal and thermo-oxidative stability of the polymers. Free standing and transparent films with good mechanical stability were obtained from the phosphonic acid functional homopolymers, diblock and triblock copolymers. Combining these basic properties with the advantages mentioned above makes ROMP a promising pathway for accessing a wide diversity of phosphonated macromolecular structures. These new phosphonated polymers will open new perspectives in advanced application areas, which require a high level of control over polymer structure. (C) 2013 Elsevier Ltd. All rights reserved.