This paper seeks to explore the implementation of corporate ethical culture and policies as an adjunct to formal forms of corporate governance. The insurance industry utilises a variety of external governance structures, but is almost unique in that stock companies (which are exposed to an external market for corporate control) and mutual companies (which are owned by a subset of their customers) are in active competition. A questionnaire survey of senior executives in U.K. insurance companies was undertaken to explore the implementation of ethical policies and codes, to investigate ethical attitudes, and to analyze the extent to which these policies and attitudes varied among companies. The results suggest that ethical policies have a higher profile and ethical attitudes and behaviour are more positive in mutual as opposed to stock insurance companies. These findings support the contention that a strong corporate ethical culture may be utilised to enhance formal corporate governance instruments.