We analyze the effects of the 2004 CAP reform and EU enlargement on European and world agricultural markets. We compare the results from a CAP reform only and a CAP reform plus enlargement scenarios to a no-enlargement baseline implementing Agenda 2000 CAP policies. We utilize the Food and Agricultural Policy Research Institute's policy analysis model to simulate the effects of CAP reform and EU enlargement on production, consumption, and trade for the EU, its New Member States (NMS), and major players in world agricultural markets. The model is a partial-equilibrium model of world agricultural markets including important producer and consumer countries in world livestock and products, dairy, grains, oilseeds and products, cotton and sugar markets. Each country's commodity sectors are modeled with structural equations which incorporate all important policy parameters. With prices in most commodities in the NMS historically below EU-15 prices accession leads to substantial price increases for many commodities in the NMS. Higher prices stimulate production and dampen consumption in the NMS, and trade between the new members and the EU-15 increases. Prices in the EU-15 decrease moderately. The impact of the two reforms on world markets is negligible. The CAP reforms have their greatest impact in the EU-15 markets for meats, rice, rapeseed, and dairy products. CAP reforms without enlargement generate a small increase in world and EU commodity prices.