In 2005, the Millennium EcosystemAssessment (MA, 2005) provided the first comprehensivereport on global ecosystems, the dependence of humansocieties on the services provided, current state, andlikely future trajectory. The MA identified the failure tovalue ecosystem services as a major contributing cause. The2001 environment strategy did not explicitly addressenvironmental valuation, although the focus on poverty andenvironment implies a need for valuing natural resources andenvironmental services. In consultations on the 2010environment strategy, a wide range of stakeholders stressedthe importance of mainstreaming environmental services. Tobetter direct limited resources for environmental valuationand training, a closer look is needed to identify theconditions under which valuation has had an impact on:policy and project design, policy dialogue in clientcountries, environmental investments, and strengthening thecapacity of national institutions. This report presents areview of environmental valuation in World Bank operationaland analytical work, identifying what has been done, and theimpacts environmental valuation has had. The reportidentifies the conditions under which valuation is mostlikely to influence decision-makers, and finally, theimplications for the 2010 environment strategy. The reportis organized as follows: section one gives context; sectiontwo gives introduction; section three gives approach tolearning from past experience; section four focuses oncoverage of ecosystem services; section five presentsprioritizing environmental valuation; section six deals withwhy environmental valuation not done; and section sevengives recommendations.