A large proportion of the most important legislation considered by the U.S. House of Representatives is now referred to more than one committee. This study examines the impact that multiple referral has had on committee, party, and leadership relations in the House. Using spatial theory, legislative outcomes are compared under varying conditions including types of referrals, restrictions on floor amendments, and opportunities for obstruction and discharge. Central to the study is a consideration of the role of the majority party leadership. A model is developed that includes the Speaker who controls procedure. A number of empirical implications of the models are analyzed as well. These include a consideration of the relative obstructiveness of committees given referral conditions, the choice of restrictive versus non-restrictive amendment rules, and the choice of referral conditions by the Speaker.