Professionalism implies ethical responsibilities because society relies very much on engineers' knowledge and judgment to deliver their service. Every engineer is in a way an expert in their own field. Clients, colleagues and the public rely on engineers' advice in making critical decisions, including decisions affecting the use of resources, the environment, public health and safety. Because of this special status, a high level of professionalism is necessary in order to give clients, colleagues and the public a high level of confidence. Therefore, an engineer should abide by a high ethical standard so as to maintain public confidence in his profession.

Professionalism covers a very wide context including not only advice an engineer gives but also how an engineer behaves in conducting his professional work. In a broader sense, it also covers an engineer's honesty, integrity and the ability to consider public interest as the overriding requirement.