This study is intended to contribute to the setting of priorities for agricultural research in two regions of northern Syria. A whole-farm economic model based on production data from 8-year field trials, and market and farmer surveys for the same years, is used for each region. The models are run with 10% increases in approximately 30 parameters of the farming system, and the parameters are ranked according to their effect on whole-farm profit. Results indicate that improvements in wheat grain yields have the greatest effect on income, with improvements in lentil grain yields ranking second. Other parameters rate considerably below these two. The lower-ranked parameters include the energy content of barley grain, the lambing percentage, the energy content of lentil straw, and milk production. Extensive sensitivity analysis with plausible economic and environmental changes found that this ranking is robust under all changes for both regions studied. (C) 2002 Elsevier Science Ltd. All rights reserved.