This chapter addresses the ethical considerations essential to Applied Cognitive Task Analysis (ACTA). Key topics include the importance of obtaining informed consent, minimizing harm during data collection, and maintaining confidentiality and data integrity, especially in sensitive environments like healthcare and military settings. It also examines the risks of dual-use dilemmas, where cognitive insights could be misused, and stresses the need for responsible dissemination of findings. By adopting ethical practices, including robust informed consent, distress protocols, and cybersecurity measures, ACTA researchers can ensure their work adheres to high ethical standards while fostering trust and safeguarding participant welfare.