Gas Chromatography (GC) based on fatty acid profiles and API system (API 20NE and API CH50) techniques were used to identify several bacterial isolates isolated under sterile conditions from the guts of apterous adults and immatures of pea aphid. Pea aphids harboured two bacterial forms in their guts; Cocci Bacterial Cells (CBC) and Rod Bacterial Cells (RBC). Significantly greater density of RBC was obtained in the distal part of the gut than that in the proximal part. Adults and immatures of pea aphid harboured RBC in their guts. The first and second nymphal instars had no CBC. Adults harboured higher densities of CBC and lower densities of RBC than immatures do. Taken as a whole, the guts of apterous adults and immatures of pea aphid contained at least 9 species of cultivable bacteria in five genera. Stenotrophomonas maltophilia was found in 31.9% of the samples, was the genus most frequently isolated from the aphid`s gut, followed by Bacillus licheniformis. Comamonas acidovorans, Pseudomonas putida, Pseudomonas sp., Micrococcus luteus and Micrococcus varians were absent in the 1st and 2nd nymphal instars.