The increasing complexity of civil construction projects and the inherent risks of their development make it essential for civil engineers to understand not only the technical aspects but also the legal foundations governing their professional practice. This article aims to analyze the civil, criminal, ethical, and environmental responsibilities of civil engineers under Brazilian law, highlighting the interface between engineering and legislation. The methodology consisted of a bibliographic and documentary research with an exploratory and descriptive approach, based on a review of legal instruments—such as the Federal Constitution, the Civil Code, the Penal Code, the Consumer Defense Code, the Environmental Crimes Law, and the CONFEA/CREA regulations—as well as doctrinal works and recent academic articles. The results indicate that professional practice is defined by regulations that impose strict duties of prevention, damage repair, and ethical conduct on engineers, encompassing civil liability on an objective basis—regardless of fault—as well as criminal and consumer-related implications. Furthermore, it was observed that ethical performance and proper application of legal standards reinforce the safety of construction works, the protection of the environment, and society’s trust in the profession. It is concluded that civil engineering education should incorporate legal content that broadens the professional’s understanding of legal and ethical obligations, preparing engineers to prevent litigation, adopt safe practices, and act with social responsibility.