Although irrigation can greatly improve the world's capacity to feed itself by increasing agricultural production, most irrigation projects fall short of this goal. These failures are due sometimes to defective design, but more often to the expense involved, poor management and leadership, and improper use of resources. A sound system of evaluation can improve the effectiveness of these projects. This report examines A.I.D.'s current evaluation process and recommends revisions to improve project design. After reviewing the current status of irrigation in the developing world, the authors discuss A.I.D.'s evaluations, which typically concentrate on a project's conformity to its original purpose or on the performance of the implementing agency. The study found no evaluations which look comprehensively at a project's three stages -- preparatory, construction, and operational -- or examine and compare basic themes of irrigation project designs. Recommendations are: (1) that in order to improve project management and design, far greater use be made of evaluative data; (2) that evaluations focus on donor, host country government, and user needs; (3) that a grid of analytical questions/criteria be used consistently in evaluating each project; (4) that use of local public and private institutions in evaluating projects be increased; and (5) that evaluations stress management and environmental issues and farmer risk responses. Finally, evaluation guidelines designed around five major components are presented for routine use at each of a project's three stages. The five areas are economic viability; use of land, water, capital, and labor resources; performance and management of the water system; environmental effects (including health impacts); and social soundness, including effects on production and income distribution. At least one project from each of A.I.D.'s four regional bureaus should be selected for more detailed examination, and an overview of the irrigation in each region where A.I.D. has or will have irrigation projects should be developed. A 107-item reference list (1967-80) and annexes on related UN projects, environmental considerations, and criteria for project site selection are appended.