University of California Cooperative Extension farm advisors have conducted applied research to quantify processing tomato [Lycopersicum esculentum (L.) Mill] varietal performance, as a coordinated activity, since 1973. Early and midseason maturity varieties are annually evaluated at four to six locations throughout the state. The test varieties are selected in collaboration with seed companies, processors and growers. The growers and seed companies provide financial support for the tests. Most tests are conducted in production tomato fields and are harvested using commercial harvesters. The results are widely disseminated through an annual report to the funding sources, farm advisor research reports, newsletters, production meetings, the California Tomato Grower magazine, and popular media. The information obtained for fruit yield potential, fruit quality and plant horticultural characteristics is used by processors, growers, and seed companies to make variety selection decisions. This regional extension program has proven to be an effective way to generate well-designed replicated information for making intelligent processing tomato cultivar decisions and has been well accepted by the California industry.