Conditions were developed for the synthesis of high molar mass polynaphthalimides and polynaphthoylene benzimidazoles, containing perylene and anthantrone residues, from corresponding prepolymers based on 1,1′-binaphthyl-4,4′,5,5′,8,8′-hexacarboxylic dianhydride and their structure and properties were evaluated. It was shown that polymer derivatives of perylene are obtained by reductive cyclization of prepolymers in dilute solutions, anthantrone derivatives- by ring-formation in sulphuric acid and weak oleum, and derivatives containing units of both types - by thermal-ring formation of prepolymers at temperatures higher than 300°C. It was found that the polymers obtained formed rings to the extent of 70–90%, had intrinsic viscosity of 0·6−1·1 dl/g and formed films and fibres.