A model to predict ammonia losses from sprinkler applied animal wastes was developed; in order to accomplish this, a review of literature was performed to determine possible methods of predicting ammonia losses during sprinkling. As adaptability to a large variety of situations was considered of maximum importance, the number of independent variables was amplified. Earlier literature provided a model of one droplet's ejection from a nozzle, flight, and evaporation. To this model were added equations predicting volatilization of ammonia during flight. Arguments were presented to support the expansion of losses from an "average" droplet for the system to describe losses for the entire system. The resulting model predicted a sigmoidal variation of percent ammonia loss with pH, losses increasing rapidly between pH 8 and pH 10. Variation of loss with temperature was nearly linear, with slope increasing with increasing pH. The relationship of percent ammonia loss to droplet size, droplet velocity, nozzle height, and distance travelled were also examined. Ammonia losses from sprinkler applied lagoon effluent at the Oregon State University Swine Research Center were determined by analyzing ammonia concentrations in the waste before and after spraying. Resulting data were compared to the model's predictions. The effluent had a constant pH of 7, thus losses were small, but the analyzed percent loss matched the predictions within the limitations of the methods of analysis. Models and data from earlier studies were cited to support predictions at higher pH.