Abstract: The doctrine of corporate opportunities provides that corporate fiduciaries cannot, without consent, divert and exploit for their own benefit any opportunity that should be deemed an asset of the corporation. Although courts and commentators agree on the policies underlying the doctrine, a variety of often conflicting tests have arisen to determine when a given opportunity properly should be termed a "corporate" one. In this Article, Professors Brudney and Clark criticize the vagueness of the various standards currently applied, and argue that a principled doctrine should distinguish, as the contemporary one does not, between contexts involving public corporations and those involving close corporations. In the former case, a categorical ban on diversion is usually appropriate; moreover, separate rules are appropriate for full-time executives, outside directors, and parent companies. In cases involving close corporations, a more flexible, selective approach should govern in light of the essentially contractual nature of the close corporate venture.