The mussel Perna viridis, commonly known as Green Mussel, is native from the Indo-Pacific region and has been introduced in various countries around the globe. In Brazil, the species has already been recorded in Rio de Janeiro and Ceará states. With the aim of assessing the presence of mussels in the southern region of the country, 14 individuals were collected in the Paranaguá Estuarine Complex, Paraná. The mussels were found attached at a depth of 2 m on the artificial structure of Ponta do Poço Marina. The DNA was extracted using a commercial kit, the COI gene was amplified through PCR using the primers dgL-CO-1490 and dgHCO-2198, sequenced by the Sanger method, and the species was identified through the BOLD Systems. The phylogenetic tree was built on the software MEGA 11 using 28 sequences from three Perna species. Therefore, the present study confirms the occurrence of P. viridis in Brazil through molecular identification for the first time and adds a second Brazilian state where it has been recorded. The Brazilian coastline provides optimal environmental conditions for the establishment and development of P. viridis.