Seroepidemiology is use of serology to study disease in populations, and the specificity and sensitivity profile of many serologic tests makes them ideal as screening tests in flocks of aviary birds. However, an understanding of the serodiagnostic method used, its sensitivity and specificity and the disease process itself, and how it behaves in individual birds as well as in contact populations is very important before judgments can be made on the results that are obtained. In this review, some of the more commonly used serodiagnostic methods used in aviculture are summarized.