The 2014 outbreak of the Ebola virus disease in West Africa has taken a devastating human toll. Although the outbreak originated in rural Guinea, it has hit hardest in Liberia and Sierra Leone, in part because it has reached urban areas in these two countries, a factor that distinguishes this outbreak from previous episodes elsewhere. As of October 3, 2014, there had been 3,431 recorded deaths out of 7,470 probable, suspected, or confirmed cases of Ebola. This report informs the response to the epidemic by presenting best-effort estimates of its macroeconomic and fiscal effects. Any such exercise is necessarily highly imprecise due to limited data and many uncertain factors, but it is still necessary in order to plan the economic assistance that must accompany the immediate humanitarian response. The goal is to help affected countries to recover and return to the robust economic growth they had experienced until the onset of this crisis. This document presents the World Bank's preliminary estimates of the economic impact of the Ebola outbreak in West Africa for 2014 (short term impact) and 2015 (medium term impact). Section 2 presents a single set of 2014 estimates for Liberia, Sierra Leone, and Guinea, based on available data on current economic activity as well as assumptions about the short-term impact. It also presents current data on the limited current impacts on other countries in the region. Section 3 presents estimates for the impact by the end of 2015 for Liberia, Guinea, and Sierra Leone, as well as estimates for West Africa as a whole. Because the epidemic and the behavioral responses to it have more time to diverge over the course of 2015, Section 3 presents two scenarios for 2015, which vary in the optimism of their assumptions regarding the epidemic and the success of donor and government policy and efforts to control it. The take-away messages from this analysis are a low Ebola scenario that corresponds to rapid containment within the three most severely affected countries, and a high Ebola scenario corresponds to slower containment in the three countries, with some broader regional contagion. A swift policy reaction by the international community is crucial. With potential the economic costs of the Ebola epidemic being so high, very substantial containment and mitigation expenditures would be cost-effective, if they successfully avert the worst epidemiological outcomes. To mitigate the medium term economic impact of the outbreak, current efforts by many partners to strengthen the health systems and fill the fiscal gaps in the core three countries are key priorities. Finally, this report does not take into account the longer term impacts generated by mortality, failure to treat other health conditions due to aversion behavior and lack of supply capacity, school closings and dropouts, and other shocks to livelihoods. It is truly focused on the short and medium-term inputs, over the next 18 months.