Background: Mycoplasma gallisepticum (Mg) is the most pathogenic and economically important bacterial respiratory pathogen of poultry. Objective: monitoring the incidence of Mg infection in Monofia and Gharbia Governorates by cultural , PCR and molecular characterization of the isolates to assess their genetic relatedness with other selected MG isolates circulating in Egypt and other countries Methods: 194 tissue samples and 50 tracheal swabs from broiler chickens floks from Monofia and Gharbia Governerates were cultured followed by molecular typing of lipoprotein gene of three Mg isolates.. Results: Mycoplasma gallisepticumg incidence by culture method were (6.2%) & ( 4.4%) in Monofia and in Gharbia respectively. By using PCR Mycoplasma gallisepticumg incidence were (8.46%) &( 7.02%) in Monofia and Gharbia respectively. Partial sequencing of lipoprotein gene for three Mg isolates was applied. The generated phylogenetic trees showed similarity with varying percentages between isolates MW689244, MW689245 and MW699359 and other selected isolates of Mycoplasma gallisepticum circulating in Egypt and other countries .Strain MW689244 showed 100% nucleotide and amino acid identity with Chinese strain QHDT-1 KY088057. The three isolates belong to one clade with Avipro vaccine CP028147 Conclusion: PCR was more sensitive than culture.. Typing of Mycoplasma gallisepticum using lipoprotein gene indicated that the circulated Mycoplasma gallisepticum strains are mutant type of Mg F vaccine strain.