There are many reports about thelastomatid parasitic nematode isolated from different species of cockroaches in many countries, without any clear information about those nematodes that are associated with Polyphaga aegyptiaca until now, so we have examined the nematodes were recovered from P. aegyptiaca and collected from Sharkia Gov., Egypt. Hammerschmidtiella diesingi and Leidynema appendiculata were found with the high infection rates in P. aegyptiaca. The results indicated that the prevalence of cockroaches infected with H. diesingi alone or integrated with another species was (51%), similarly, L. appendiculata was (65%) from total cockroaches. The mean intensity of L. appendiculata was higher than H. diesingi the current of cockroaches. The gravid females of both H. diesingi and L. appendiculata were also higher than of any other stage of nematodes. Finally, using light and electron microscope, in order to identify and determine the morphological characteristics of both species of nematode. Results also indicated that SEM is a powerful tool to identify the morphological characteristics such as head, female cephalic region, vulva, tail, anus, male cloaca area and papillae.