The task of carrying out such an audit demands the skills of a mixed team of specialists. The audit is procedural in nature, and the steps to be performed in carrying it out are the same as those applied to any other 'systems' audit. In most cases, the power of the computer will be needed to assist in performing the audit. Without efficient personnel, adequate system security will never be achieved. The paper highlights means of ensuring the physical security of the computer installation, discusses the sophisticated software techniques used to maintain efficient data access control, and assesses the tasks and stages involved in performing a systems security audit. (Author summary modified)