Information systems are becoming increasingly critical to the daily operations and success of many firms. This, combined with the rising investments in design and development of these systems, make implementation a high priority research topic. Although information systems implementation has been a topic of interest to researchers over the past two decades, the extent to which the existing body of research reflects substantial and cumulative development is not entirely clear. The objective of this study is to conduct a rigorous and quantitative review of the empirical DSS implementation literature as a basis for providing guidelines for implementation management and conduct of future research. Metaanalysis of 144 findings from 33 studies indicates that user-situational variables (involvement, training and experience) are more important than psychological factors to DSS implementation success and that user-situational variables can improve the implementation success by as much as 30 percent. Furthermore, the meta-analytic findings regarding the methodological characteristics of studies provide useful insights for the design of future research studies of implementation. The findings also allow us to put into perspective the incremental contribution of additional substantive and empirical studies in this area. Additionally, several specific domains (e.g., construct validation research on user involvement and casual modeling) might profit most from future research efforts.