Species of root-knot nematodes occurring in South Africa (Meloidogyne fallax, M. chitwoodi, M. javanica, M. incognita, M. arenaria and M. hapla) were identified and differentiated by the sequence characterised amplified region - polymerase chain reaction (SCAR-PCR) technique. Multiplex internal transcribed spacer (ITS)-PCR amplified a fragment in an unknown species for which no SCAR-PCR marker was available. M. fallax, a quarantine organism in Europe, was recorded for the first time in South Africa. The geographical distribution of M. chitwoodi is extended to four localities in South Africa. The SCAR-PCR technique reliably determined species composition, detecting mixed populations of M. hapla, M. fallax and M. chitwoodi on groundnut and of M. arenaria and M. incognita on Impatiens spp. In contrast, single species populations of M. javanica and M. incognita and the unknown species were detected in glasshouses.