Gambling is a popular pastime in the United States, and it is important that we understand the class of behaviors in a behavior analytic context. The relationship between the function and preference of gambling behavior remains yet to be explored. The purpose of these two studies is to examine this relationship. Participants were asked to play a set of four computerized slot machines. Each slot machine was tied to a separated function-based outcome which they could win. In study 1, 80% of participants had a distinct preference for a single outcome. In study 2, the participants were also administered the GFA. Seven participants completed the MSWO. The relationship between the results of the GFA and the results of the free operant preference assessment did not support the hypothesis. Among other results, was data suggesting that those who score 0's on their GFA's may significantly affect the data and that the MSWO and free operant preference assessment have a strong high correlation.