Suggestions have been made for total abolition of the ultra vires doctrine in relation to the powers of limited companies, but so far these have not been adopted either in England in the Companies Act, 1948, or in New Zealand in the companies Act, 1955. As the ultra vires doctrine therefore still forms part of company law, it is proposed to examine it critically insofar as it applies to the memoranda of companies and to consider the value of the doctrine to the modern law. This task of examination will be attempted by tracing the development if the doctrine to its modern form, by considering the attempts which have been made to evade its operation, by discussing its effect on the company and on third parties and by comparing its operation and effect with other corporate bodies. It is hoped that by analysing every aspect of the doctrine, its advantages and disadvantages will be apparent and that a correct assessment of its value can be made. The inevitable conclusion it is submitted, will be that the doctrine has become not only worthless, but a hindrance to freedom of commercial transactions.