Purpose: The present work consists of a comparative study of two indexes of skeletal maturation: the carpal index (SMI) and the vertebral index (CVMI) and verification of the reliability of the vertebral index in the determination of the stages of the skeletal maturation.Methods: Radiographies from the dental records of treated patients from Universidade do Sul de Santa Catarina (UNISUL) were used. The sample was composed of 158 radiographies comprising seventy-nine carpal and seventy-nine lateral cephalometric radiographies of patients of both genders between six and eighteen of age. The carpal radiographies were analyzed using Martins' method and the lateral cephalometric, according to Baccetti, Franchi and McNamara Jr.Results: The Spearman's correlation test results showed a significant correlation coefficient of 0.616 between SMI and CVMI and the Pearson's test, of 0.698 for both genders (P<0.0001). The correlation between the indexes and the chronological age was 0.775 for SMI using Spearman's test, and 0.974 using Pearson's correlation test. For the CVMI, Spearman's correlation was 0.563 and Pearson's was 0.717, showing that there is a statistically significant correlation.Conclusion: The SMI is the safest and most trustworthy method to evaluate the skeletal maturation, although the CVMI can be used as a substitute method when there is conversance with the morphologic alterations of the vertebrae and when the carpal radiography is not available in the patient's orthodontic records.