Usually the sale of goods takes place between the buyer and either the owner of the goods or by his authorised agent. However, there are some circumstances in which a seller may purport to sell goods which he does not have any right to sell. In these circumstances the law has to decide which of two innocent parties to favour: the buyer or the original owner. It is at this stage that the nemo dat quod non habet rule comes into play. This essay will consider the operation of this rule and whether the exceptions to it offer an effective compromise to what would otherwise be a very harsh rule.