Genetic markers of the Y chromosome are powerful tools for investigating paternal ancestry and are widely used in population and forensic genetics. However, in order to obtain statistics with a higher degree of certainty using these markers, it is necessary to obtain haplotypic frequencies from a representative database, as well as knowing the diversity and structure of the population. The aim of this study was to investigate the genetic diversity of a sample of 1114 unrelated men from three states in the Northeast of Brazil: Paraíba, Pernambuco and Ceará, through the analysis of 23 Y-STRs and to contribute to the expansion of the Brazilian database on these markers. The PPY23 panel had a high discriminatory power, and the population structure was consistent with the historical aspects of the colonization of the Northeast of Brazil. Population comparisons based on paired genetic differentiation values (Fst) revealed no statistically significant differences between the three populations in this study. However, it was observed that Pernambuco and Paraíba were genetically closer to states outside the Northeast region. Y-STR-based haplogroup prediction, carried out using the NevGen software, revealed that the paternal lineage of the populations in this study is essentially European, with little African or Native American influence, just like the rest of the Brazilian population. Additionally, this work contributes to a more representative database for use in forensic and population genetics.