A table of exact 95 percent confidence limits for differences and ratios of two proportions and their odds ratio, including one-tailed P values for the Fisher-Irwin exact test, is given for a wide variety of 2 × 2 tables with sample sizes of 20(20)100. The calculations are based on Fisher's [3] conditional theory, and the computer algorithm of Thomas [10 or 11] is used to produce the tables. It is shown how the tables may be used for sample size determination without fixing the power for a given alternative hypothesis.