A total of 170 lung samples, 85 of which from Balady cattle and 85 from Friesian cattle, revealed 30 mycoplasma isolates (1 7.6%). The Balady lung samples revealed 19 mycoplasma isolates, 5 of which were from normal lungs, typed as 2 M.bovirhinis and 3 were M.arginini, while 14 mycoplasma isolated pneumonic lungs were typed as 5 M.bovis, 3 M.bovigenitaliurn, 3 M.bovirhinis and 3 M.arginini. The Friesian lung samples revealed 11 mycoplasma isolates, 3 of which were isolated from apparently normal lungs, typed as 1 M.bovirhinis and 2 were M.arginini, while 8 mycopasma isolated from pneumonic lungs were typed as 4 M.bovis, 2 M.bovigenitalium, 1 M.bovirhinis and 1 M.arginini. Antibiogram was made for the isolated mycoplasma species against 17 antibiotics. They were highly sensitive to Trospectomycin sulphate, Enrofloxacin, Norfloxacin, Tiamulin and Ciprofloxacin. Pathogenicity study was made by injecting the isolated mycoplasma strains intraperitoneally into mice. The test resulted in congestion of the lungs injected with M.bovis and M.bovigenitalium after one week of infection, and mycoplasmas could be reisolated from the lungs.