Four techniques, i.e., perineal patterns, isozymes, specific sequence characterised amplified region-polymerase chain reaction (SCAR-PCR) and random amplified polymorphic DNA (RAPD), were compared for the identification of species of root-knot nematode (RKN) from Libya. The RAPD technique proved superior for species diagnosis. A population from Massa that could not, because of atypical patterns, be identified using either perineal patterns or isozyme phenotypes, showed amplification patterns consistent with those of M. incognita. A new esterase phenotype is described for this population. Single egg mass lines from two other locations, Elhamma and Durnah, were identified as M. javanica, whereas those from Aun Mare were identified as M. incognita. RAPDs were used to examine the relationships between the Libyan isolates and isolates of Meloidogyne spp. from elsewhere. This technique revealed differences in the Libyan isolates of M. incognita that distinguished them from isolates from other geographic origins. The work demonstrates the potential to utilise the RAPD technique in an integrated programme to control RKN.