Do states act as laboratories for reform? Are state administrative agencies likely to adopt policy innovations? This study analyzes the adoption of environmental policy innovations by state administrative agencies in the area of hazardous waste regulation. Four explanations are developed to explain the factors that affect innovation adoption: the severity of the problem, the importance of institutional factors, the role played by interest groups, and contextual factors. Institutional factors, such as state wealth and administrative professionalism, are important determinants of innovation adoption. State agencies are also likely to adopt innovations to deal with problems created by hazardous waste contamination. In addition, state environmental managers are not directly influenced by interest groups, and the inclusion of all stakeholders is likely to lead to greater support for new policy initiatives. Implications for practitioners are drawn based on the study's findings.