Group B Streptococcus (GBS) is a leading agent of neonatal invasive disease, and the hypervirulent ST17 is the most associated with meningitis. CRISPR elements are ubiquitous in GBS, and their analysis may provide valuable insights on evolutionary aspects, especially regarding the exchange of genetic material. Here, we evaluated the diversity of CRISPR elements among 17 GBS isolates belonging to ST17, including 9 recovered from anovaginal samples (carriage) and 8 from invasive disease (iGBS) in newborns (3) or adults (5), from 1991 to 2020 in Brazil. Genomic data was used to identify CRISPR spacers and Cas sequences using the online tool CRISPRCasFinder. CRISPR1 locus (CAS-TypeIIA) and the same 36bp Direct Repeat (DR) were found in all isolates. Overall, CRISPR spacers varied in number according to the clinical source. Half of iGBS had 9 spacers, while the remaining four isolates had 10, 11, 12 or 16 spacers. Carriage isolates, in turn, mainly had 8 spacers (33.3%), while 4, 7 or 10 spacers were harbored by two isolates each. Certain spacer configurations were exclusively found within a single source, such as 8 spacers in carriage and 9 spacers in iGBS. Also, carriage isolates had fewer spacers than iGBS overall. There was a trend of spacer loss over time, with more ancient isolates (1991-2010) presenting 10-16 spacers while more recent isolates (2015-2020) presented 4-10 spacers. Our results suggest a weaker “defense” against foreign genetic material within a subset of ST17 isolates in Brazil, highlighting those recovered from carriage and/or in more recent years.