This paper examines the economic impact of swine research undertaken by Agriculture Canada from 1968 to 1984. The economic surplus approach is used to estimate the returns to this research and to determine the distribution of benefits between producers and consumers. The ex ante and ex post approaches to measuring changes in producers' surplus are compared. The impact of the marginal excess burden of taxes on measures of net benefits from research is examined J The internal rate of return of net benefits from research is examined J The internal rate of return to expenditures on swine research was found to be between 45% and 50% at the margin. About 85% of the benefits accrued to Canadian hog producers.