This essay focuses on opportunity crisis, a neglected topic within the rubric of crisis studies. The contributions of this research are both conceptual and empirical. Conceptually, it defines opportunity crisis, outlines a framework for its analysis, distinguishes it from the standard threat crisis, and considers the differences between these two variants of international crises in terms of their onset, process and termination. Empirically, the 106 opportunity and 187 threat crises identified in the International Crisis Behavior (ICB) data set, over the 1918-1994 period, are observed in order to test several postulates on the unique attributes of an opportunity crisis, and on the distinctions between opportunity and threat cases. The study points to a clear conclusion: the stress gap, which is the conceptual distinguishing element between threat and opportunity crises, is responsible for distinctive interaction patterns and crisis outcomes specific to opportunity crisis. The findings support this pretheory in every category with some exception regarding gravity. Indeed, opportunity crises exhibit more violent triggers and more severe gravity than threat cases. Similarly, interactions in crisis and the role of violence vary by type of crisis. Threat cases exhibit more violence in the primary crisis management technique (CMT) used by target-states and its scope tends to be more severe. Opportunity cases manifest an opposite trend: target-states use more pacific political-diplomatic CMT's, capitulating to the catalyst's demands. If violence is present, its scope is low. Termination, like interactions, varies in type between opportunity and threat crises, in correspondence with the framework postulates on content, form and legacy. The outcomes of opportunity crises tend to be definitive: victory for the initiator and defeat for the target-state, taking the form of either an imposed agreement or a unilateral act. These cases are more likely to escalate later in the course of an on-going conflict. By contrast, threat crises are more ambiguous in content and their termination is likely to take the form of a formal/semi-formal agreement or tacit understanding which reflects target-state willingness to compromise. Consequently, the post-crisis legacy of threat cases is less likely to involve future escalation among adversaries. Since this study identifies opportunity crises as distinct phenomena, separate from traditional threat crises, its theoretical implications call for future development of separate frameworks for each subgroup of international crisis and draw attention to additional research topics, such as power and regime, which affect opportunity and threat crises in world politics.