A survey of plant parasitic nematodes associated with the rhizosphere of cotton cvs. Giza 86 and 45 grown in fourteen locations of Dakahlia and Damaita governorates was carriedout during the cotton growing seasons of 2005 and 2006, , in addition, a pot experiment was conducted to determine host suitability of three cotton cultivars i.e. Giza 86, 89 and Giza 45 to Meloidogyne incognita infection under greenhouse condition at 30±5ºC . Twelve nematode genera were recorded in cotton fields surveyed in Dakahlia governorate, whereas nine nematode genera only for those of Damaita governorate. Based on their frequency of occurrence these genera can be arranged in descending order as follows: Tylenchus (46.3%), Tylenchorhynchus (39.7%), Xiphinema(23.9%), Meloidogyne (19.0%), Rotylenchus (10.7), Hirschmanniella (9.1%), Trichodorus (8.25%) ,Hoplolaimus(7.49%), Rotylenchulus (7.4%), Helicotylenchus (4.9%) , Psilenchus (1.6%) and Pratylenchus (0.82%),for Dakahlia , whereas Meloidogyne (68.0%) , Tylenchus (64.0%), Tylenchorhynchus (60.0%), Heterodera (38.0%), Dorylaimus (14.0%), Hirschmanniella (10.0%), Helicotylenchus (8.0%) ,Aphelenchus ( 8.0%0) and Psilenchus (2.0%) for Damiata. cotton cv. Giza 86 appeared to encounter the highest number of nematode genera (10) while Giza 45 gained (5) only. Screening of the selected cotton cultivars against M. incognita infection revealed that plant growth parameters tested were obviously affected to a certain extent, where cotton cv. Giza 89 showed the least percentage reduction for shoot and root lengths, and total plant fresh and shoot dry weights with values of 4.9, 7.5, 2.5 and 0.44%, respectively, On the other hand, cotton cv. Giza 86 and 45 recorded the highest percentage reduction values for the same growth parameters. Based on root-gall index and R factor of M. incognita infecting cotton cultivars tested, Giza 89 was scored as resistant while Giza 45 as well as Giza 86 were scored as susceptible hosts since their root gall indices were 2, 5 and 4 with R factor values of 0.4, 2.31 and1.11, respectively.