A coccal-shaped organism, designated 516(T), was isolated from yan-tsai-shin (fermented broccoli stems), a traditional fermented food in Taiwan. 16S rRNA gene sequencing results showed that strain 516(T) had 98.9 % sequence similarity to that of the type strain Lactococcus garvieae NBRC 100934(T). Comparison of three housekeeping genes, rpoA, rpoB and pheS, revealed that strain 516(T) was well separated from Lactococcus garvieae NBRC 100934(T). DNA-DNA hybridization studies indicated that strain 516(T) had low DNA relatedness with Lactococcus garvieae NBRC 100934(T) (46.1 %). The DNA G+C content of strain 516(T) was 38.1 mol% and the major fatty acids were C16 : 0 (22.7 %), C19 : 0 cyclo ω8c (17.9 %) and summed feature 7 (29.0 %). Based on the evidence, strain 516(T) represents a novel species of the genus Lactococcus, for which the name Lactococcus formosensis sp. nov. is proposed. The type strain is 516(T) ( = NBRC 109475(T) = BCRC 80576(T)).