Cytogenetic studies on Cycloramphus boraceiensis Heyer, 1983 collected in Picinguaba, Ubatuba, State of São Paulo are presented. The species has 2n=26 karyotype formed by metacentrics, submetacentrics, and one telocentric pair which carries Ag-NORs. The C-banding patterns is also described.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)