The present contribution describes an unsophisticated yet highly efficient process to make dicarboxyl telechelic isotactic polypropylene containing pendant nitro groups via the oxidative degradation of commercially available crystalline polypropylene with nitric acid. The obtained crystalline polymer has a narrow molecular weight distribution (M-w/M-n = 2-4) and maintains the same degree of isotacticity as the virgin polypropylene. The molecular weights of the product can be well controlled by varying the reaction temperature, reaction time, or the concentration of nitric acid. It was found that the higher reaction temperature and higher concentration of nitric acid, the faster the degradation is. Kinetic studies shown that the reaction is 4.2 orders in nitric acid, indicative of the complex nature of the reaction mechanism. Both liquid/solid and gas/solid interface interactions were found simultaneously existing in the present system. The carboxyl-capped polypropylene with low NO2/COOH ratio can be produced at a higher reaction temperature with a higher concentration of nitric acid. Importantly, the nitric acid utilized in the reaction can be recycled and reused in the subsequent reaction. Other functional (acyl chloride, allyl, ester, amide, and hydroxyl) capped isotactic polypropylenes have been readily made through the transformation of the carboxyl group of the dicarboxyl telechelic isotactic polypropylenes in high yields.