in olive growing areas of south and north of Algeria to identify plant parasitic nematodes associated with this crop. Sixteen genera of plant-parasitic nematodes were identified. Among them four are considered as having economic importance for olive. Among these the endoparasites Pratylenchus spp. were detected in the majority of the sampled areas and were the most frequent. Meloidogyne spp. were also present in some areas. Helicotylenchus spp. were present with a high frequency in almost all surveyed sites. Among the ectoparasites, only Xiphinema spp. have potential to damage olive. Other nematodes of less importance were poorly represented. Nematode densities varied according to taxa identified and areas surveyed. Excepted Pratylenchus spp. and Helicotylenchus spp., the others taxa are reported for the first time on olive in Algeria.