Twelve broiler farms and one hatchery were examined for presence of arthritis in Kaliobia Province. The morbidity rate ranged from 0.5 % in baby chicks to 20% in 22 day old chicks with on overall incidence of 8.35%. The higher morbidity was detected in 18-28 day old chicks. The bacterial affections raged form 8-  26.31 % except in baby chicks reach 60%. 129 bacterial isolates were recovered from the joints and internal organs of 47 birds. All strains were subjected to specific biochemical tests according to the morphological and staining characters. Staphylococci was isolated in a percentage of (28.7 % followed by salmonellae (24.8%); E. coli (19.4%) mycoplasma (17.8%), streptococci (8.5%), then corynebacterium (0.78%). Serological tests were done to some types according the availability of antisera). Thirteen strains of E. coli were typed as O 114: K; I 128: K67 and O 119. K69 serotypes. Thirty – two salmonellae were typed, 20 as Poly 1 and 12 as poly I & II. Twenty-three Mycoplasma isolates were typed by growth inhibition test as Mycoplasma Gallisepticum (MG) by using specific antisera. Four out of 60 arthritic birds, were positive for MG (6.6%) recovery, and 8 birds (13.3%) had antibodies titer against MG and MS in a percent of (87.5% and 12.5%) respectively