This investigation was to determine whether monoclonal antibodies (Mabs) could be used to differentiate coagulase-negative staphylococci (C-NS) at species and strain level. Mabs were produced to four Staphylococcus epidermidis strains, two S. haemolyticus strains, one S. saprophyticus strain and one S. warneri strain. A panel of nine antibodies was tested for species and strain specificity against five type strains and 65 clinical isolates of C-NS by enzyme-linked immunosorbent assay (ELISA). Species specificity was found with Mab D150 produced to one S. haemolyticus strain. Using Mab D150 and Mab D198 in conjunction, identification of 90% of S. haemolyticus isolates to species level was achieved. S. saprophyticus Mab K84 reacted with most other strains of C-NS tested but only three S. haemolyticus strains (16%). This finding provides further evidence that S. haemolyticus possesses different surface determinants to other C-NS which could form the basis of a typing scheme for S. haemolyticus using Mabs D150, D198 and K84.