This paper describes part of a comprehensive National Air Emissions Monitoring Study (NAEMS) conducted at a swine finishing farm located in the state of Indiana, in the United States. The NAEMS was a 2-year study of emissions from animal feeding operations that produce pork, chicken meat, eggs, and milk. It provided emission data for the US. Environmental Protection Agency (EPA) to develop tools for estimating emissions from livestock farms. The study in Indiana focused on quantifying and characterizing emissions of gases, particulate matter (PM), and volatile organic compounds (VOCs) from a swine finishing quad (four 1000-head rooms under one roof). Long-term continuous and quasi-continuous measurements were conducted with 157 on-line measurement variables using an array of instruments and sensors for gas and PM concentrations, fan operation, room static pressures, indoor temperature and humidity, animal activity and feeding times, and weather conditions. Pig inventory and weight, feed type and quantity, and manure accumulation and composition were also documented. Systematic tests of the measurement system were conducted. Monitoring methodologies, instrumentation applications, equipment maintenance, quality controls, and system performances are presented and can be used as a reference in assessing research quality and improving future environmental studies on livestock facilities.