Ten Staphylococcus caprae strains isolated from four patients and responsible for bone infections following implantation of orthopaedic material were compared to four S. caprae strains collected from milk samples of healthy goats. The following characteristics were investigated: Smal patterns, hybridization patterns with pBA2 (ribotypes), slime production, adhesion to matrix proteins (fibrinogen, fibronectin, collagen) and the staphylococcal adhesion genes (fnbA, clfA, cna, atlE, ica, fbe). None of the characteristics enabled us to distinguish the human strains from the goat strains. Slime was occasionally produced by S. caprae strains but all of them carried nucleotide sequences hybridizing at low stringency with the following genes: atlE encoding a S. epidermidis autolysin binding vitronectin and responsible for the primary adhesion to polystyrene, ica operon involved in the biosynthesis of a S. epidermidis extracellular polysaccharide, and the part of clfA encoding the serine-aspartate repeated region of a S. aureus cell-wall fibrinogen-binding protein.