Speech and debate occupy a central place in parliaments, yet have not generated significant interest among scholars of contemporary political science. This is partly attributed to the notion that parliamentary debate does not have any impact on policy-making. In the last twenty years, however, legislative speech has been recognized as more varied than commonly assumed, and may be much more than the sterile argumentative confrontation of opposition and government. There are three approaches to parliamentary debate: a strategic and partisan-rhetoric approach (anchored in rational choice theory), a deliberative approach, and a discourse approach. Thischapter examines debate and deliberation in legislatures, first by providing a broad overview of the strategic/partisan-rhetoric, deliberative, and discourse approaches to parliamentary debate. It considers the basic theoretical assumptions of the three approaches and presents some major empirical findings. It gives particular emphasis tothe deliberative approach oflegislative speech and concludes with a discussion of a number of commonalities, remaining tensions, and some avenues for future research.