Natural gutta-percha is well known for its mechanical properties which derive from its particular stereochemical 1-4 trans structure. The gutta-percha contained in the various commercially available points is made of natural gutta-percha which has undergone a heating process to allow inclusion of the other elements found in its composition, especially a nonspecified coloring agent. The purpose of this study was to confirm that the stereochemical 1-4 trans structure contained in commercial points is identical to that of natural gutta-percha and that it has not been altered by the heating process inherent to its fabrication. Furthermore, we wanted to identify the coloring agent also included in its composition. Samples of commercial gutta-percha points were studied using nuclear magnetic resonance spectral analysis and compared with that of natural gutta-percha. Our results show that both natural and commercial gutta-percha mainly have a 1-4 trans stereochemical structure and that the coloring agent is erythrosin.