Repeated comments are made as to the similarity between the common intention constructive trust and proprietary estoppel, but there remains considerable confusion over the precise nature of this interrelationship. The constituent elements of each doctrine bear close comparison and, although their respective modes of operation remain distinct, they may lead to similar results. The recent redefinition of the Pallant v Morgan equity provides an opportunity to probe once more the interrelationship between these doctrines. The Pallant v Morgan1 equity explores the operation of the Rochefoucauld v Boustead2 doctrine in the context of the joint acquisition of land and demonstrates the enforceability of express oral intention based upon a wider range of unconscionablity than the detriment based conduct which dominates both the common intention constructive trust and estoppel.