One coccal strain, designated 0905C15(T), was isolated from fresh cummingcordia, which is the main ingredient of pobuzihi (fermented cummingcordia), a traditional fermented food in Taiwan. 16S rRNA gene sequencing results showed that strain 0905C15(T) had 98.22-98.82 % sequence similarity to that of the type strains of four Lactococcus lactis subspecies (L. lactis subsp. lactis BCRC 12312(T), L. lactis subsp. cremoris BCRC 12586(T), L. lactis subsp. hordniae BCRC 80474(T) and L. lactis subsp. tructae BCRC 80475(T)). Comparison of two housekeeping genes, recA and rpoB, revealed that strain 0905C15(T) was well separated from the reference strains of the genus Lactococcus. DNA-DNA hybridization studies indicated that strain 0905C15(T) had low DNA relatedness to the four Lactococcus lactis subspecies (9.7-15.24 %). The DNA G+C content of strain 0905C15(T) was 39.6 mol %. Based on the evidence, strain 0905C15(T) represents a novel species of the genus Lactococcus, for which the name Lactococcus taiwanensis sp. nov. is proposed. The type strain is 0905C15(T) (= NBRC 109049(T) = BCRC 80460(T)).