Coagulase-negative staphylococci (CNS) frequently colonize teat skin and are common findings cultured from milk samples of cows with subclinical intramammary infections (IMI). Several species are related to IMI, but knowledge about the epidemiology of CNS species is limited. Cows in automatic milking systems (AMS) may have increased risk for teat colonization and IMI because more than 60 cows are milked several times daily with the same milking unit. The objectives of this study are (1) to investigate patterns of CNS species in milk samples and teat skin swabs in nine AMS herds and (2) to identify the predisposing cow level risk factors for specific CNS IMI and teat colonization.In each herd, 30- 40 cows with somatic cell counts > 200,000 cells/ml in the previous milk recording are randomly selected and teat skin swabs and aseptic quarter foremilk samples are taken. Teat skin swabs are collected using a modified wet-dry method. First a wet swab immersed in ¼ Ringer’s solution followed by a dry swab are rotated 360° around the teat canal orifice and both swab tips transferred into one tube with 2 ml of ¼ Ringer’s solution. Samples are transported on ice for culturing in the laboratory. After vortexing, 0.01 mL of each quarter milk sample and 0.1 mL of each quarter teat swab are streaked simultaneously on Staphylococcus selective medium (SA Select) and calf blood agar. Colonies from right hind and left front quarters suspected of being CNS in milk and/or teat skin samples (cut-off five CFU) are subjected for MALDI-TOF assay for species identification. To date, preliminary results of milk and teat skin samples from 130 quarters (65 cows) are available. CNS species were identified in 86 out of 130 samples, in 69 teat skin swabs and 17 milk samples, respectively. From 11 teat skin samples and one milk sample more than one type of the CNS species was isolated. Staphylococcus epidermidis and Staphylococcus equorum were the most frequently isolated CNS species from milk samples (7/17) and (5/17), respectively. Staphylococcus equorum, Staphylococcus haemolyticus and Staphylococcus xylosus were the most frequently isolated CNS species from teat skin swabs (56/69), (9/69), and (6/69), respectively. Data collection will be finished in April 2017. The final results will give new insights into herd specific CNS species patterns for teat skin and milk. We expect that our new knowledge about CNS species specific characteristics and epidemiology will improve udder health management in AMS herds.