Mycoplasma hyopneumoniae is an enzootic pneumonia affecting swine. Globally it has been estimated that 93% of swine herds have Mycoplasma hyopneumoniae which may result in performance losses (Ross, 1992). Losses may incur from a decrease in performance, lower weight gains, decreased feed efficiency, antibiotic treatments, and an increased risk of other respiratory diseases. The objective of this study was to complete a systematic review to compare the studies and determine the effectiveness of the vaccine in relation to average daily gain (ADG). A total of 1,074 articles were considered and eight articles were used in the final report. The results of combining these final articles concluded that when vaccinated against Mycoplasma hyopneumoniae swine had an ADG of 17.91 grams per day more than non-vaccinated swine. The weighted average for all the studies that reported statistically significant differences was 29.63 grams per day more than nonvaccinated swine. Therefore, it may be beneficial for a producer, depending on their situation, to vaccinate against Mycoplasma hyponeumoniae.