Avian mycoplasmosis represents one of the most important and the costliest problems confronting poultry industry all over the world especially in breeder flocks. The mostly incriminated species are Mycoplasma gallisepticum and Mycoplasma synoviae causing chronic respiratory disease (CRD). Prevention and control programs are based on strict biosecurity, surveillance (serology, culture, and molecular identification), medication or eradication. Definite diagnosis of mycoplasmosis is the first step for control of the disease. Fastidious character of the pathogen represents a major obstacle against quick definite diagnosis. Our work intended to try and compare different diagnostic tools for Mycoplasma gallisepticum as well as an invivo and invitro medication.