Shareholder agreements reflect a reassertion of contractualism in corporate law at a time when statutory regulation is more extensive than ever. Though not displacing the s140 statutory contract between members, shareholder agreements have a role to play both in direct contract between parties but also in setting reasonable expectations that may play a role in oppression actions or winding up on the just and equitable basis. As contracts they are prima facie enforceable but also subject to statutory overlays in the form of the laws of misleading and deceptive conduct and unconscionable conduct. Finally they are subject to some limitation in that the common law suggests that a company cannot in a shareholder agreement deprive itself of its power to alter its own constitution. There is also some doubt about the extent to which directors’ duties can be attenuated by shareholder agreement and whether shareholder disputes can be made the subject exclusively of commercial arbitration and kept out of the courts.