ISO 14000 constitutes a major dilemma for most American firms in that they are not sure whether or not to actively pursue this new form of certification. This new standard is attractive as it holds the promise of helping firms become more efficient via better management of waste, yet this new standard deals with environmental performance, a potentially dangerous legal area. Both benefits and cost liabilities are very difficult to quantify and forecast. This leads to great uncertainty as to whether the benefits offered by improving environmental performance are sufficient to outweigh the costs incurred in obtaining certification. This study examines this quandary in detail and attempts to frame the path taken by firms that have made a decision. By drawing on two methodologies (Logit analysis of a large-scale mail survey of American managers and detailed field studies), this study finds that the factors influencing those firms that actively pursue ISO 14000 certification are distinctly different from those that have decided not to pursue certification at this time. For the latter, the decision is economically based; for the former, it is driven by other, more qualitative considerations. The study revealed that many of the factors expected to influence this certification did not, and observed influences differ greatly from those predicted.