The Second International Winter Wheat Performance Nursery was grown in 1970 at 38 sites in 23 countries. Four of the sites were in the southern hemisphere. Data were reported from 36 sites. The same 30 varieties evaluated in the First International Winter Wheat Performance Nursery were grown in this Second International Winter Wheat Performance Nursery. Twenty-eight varieties were winter wheats; two were spring wheats. Data on grain yield, test weight, maturity, plant height, lodging, shattering, winter survival, diseases, grain protein content and lysine content for 1970 are reported. Two-year mean data summaries also are reported