A thermoplastic composition comprises a polycarbonate having repeating structural carbonate units of the formula (1): ##STR00001## wherein at least 60 percent of the total number of R.sup.1 groups contain aromatic organic groups and the balance thereof are aliphatic, alicyclic, or aromatic groups; and wherein the polycarbonate comprises terminal groups derived from reaction with a cyanophenol of the formula ##STR00002## wherein Y is a halogen, C.sub.1-3 alkyl group, C.sub.1-3 alkoxy group, C.sub.7-12 arylalkyl, C.sub.7-12 alkylaryl, or nitro group, y is 0 to 4, and c is 1 to 5, provided that y+c is 1 to 5; optionally a branching agent; an impact modifier; and a flame retardant. The compositions are useful in the manufacture of a wide variety of parts, particularly those having a thin wall.