Abstract. The aim of this paper is to provide a critical review of the literature on the econometric analyses of firm-level determinants to eco-innovation. The review reveals some gaps in knowledge. First, an integrated theoretical framework which merges the insights from different approaches is missing. Second, the influence of some variables is still unsettled (demand-pull and cost-savings), whereas others have hardly been included in previous analyses (internal and international factors). Third, studies on the drivers to eco-innovation versus general innovation are relatively scarce with respect to those on the drivers to eco-innovation in general. Fourth, analyses of the relevance of different determinants to eco-innovation for distinct eco-innovator and eco-innovation types have largely been missing. Fifth, studies on middle-income and developing countries are still scarce. Sixth, the econometric analyses have relied on microeconometric methods based on cross-section data (mostly logit and probit models), whereas the use of panel data is virtually absent. Seventh, detailed econometric analyses on the distinct drivers and barriers to eco-innovation in different sectors and regions have not been performed so far. Finally, whether the position of the firm in the value chain and the market structure influence the propensity to eco-innovate are largely unexplored topics.