Disease monitoring and surveillance are valuable tools which are commonly used today in pig production in order to better monitor and manage the health of the pig herds. Developing the proper disease monitoring program requires a general understanding of all factors which could significantly impact the interpretation of the results obtained. The most important rule of diagnostics states “Do not run a test unless you plan on how you will utilize the result.” A such, the proper disease monitor program starts with identifying the pathogens of concern, clearly defining the goals and objectives of the program, deciding the detection target (analyte), evaluating the available sample types, determine the approach for sampling, the frequency of the sampling, as well as the proper sample size calculations. Results are the interpreted based on multiple factors including pig flow and other farm specific production parameters.