The control of corruption is an important element of governance and a stated goal of many governments. Legislative oversight is an acknowledged mechanism for controlling corruption, but little research has been undertaken on this subject, and national anticorruption strategies generally ignore the legislature. This article addresses the question of whether legislative oversight helps to curb perceived corruption, and if so, how. Statistical analysis using data from a global survey of 82 legislatures found that the presence of legislative oversight tools explains a major proportion of the variance in perceived levels of wrongdoing in countries with presidential forms of government, but much less in countries with semipresidential governments and less yet again in parliamentary systems. The analysis also found that the effectiveness of legislative oversight instruments varies by form of government. In presidential countries the most important instruments are committee hearings, hearings in plenary, and ombuds offices; in semipresidential countries they are question time, interpellations, and ombuds, while in parliamentary systems interpellations are the most important. These findings demonstrate that while the oversight apparatus is useful in helping curb malfeasance, not all tools are equally effective, and what works for some forms of government may not work as well, or at all, in other systems. Clearly, the "one size fits all" approach is inadequate when it comes to legislative corruption control.