Steel bridges comprise approximately 20% of New Zealand state highway bridges and, with the inclusion of the Auckland Harbour Bridge, represent an asset replacement value of over $2 billion. Protective coatings are often less than one third of a millimetre in thickness and are required to protect highly stressed steel from corrosion in often aggressive marine environments. Historically the full potential life of these coatings has not been achieved due to less than optimum coating selection, specification, application or maintenance. The ultimate objective of this guide is to optimise the long term capital and maintenance costs of steel structures through the implementation of best practice in the selection, application and maintenance of protective coatings on steel structures. Protective coatings for steel bridges generally provides an overview of the key processes and considerations with references to other key standards and documents. It is provided to inform and assist the wider industry in achieving best practice. However, it is also strongly recommended that specialists with skills and experience in protective coatings are used to ensure the accurate interpretation and application of this guide and various reference documents on individual projects.