This chapter introduces the importance of ethical practice in the context of mixed methods criminological research. It explains four principles that are widely regarded as the key to upholding ethical research practice, namely: avoid harm; consent and deception; privacy, anonymity, and confidentiality; and comply with the laws of the land. Ethics play a pivotal role in all research, regardless of disciplinary boundaries. Research ethics only developed as a concern in the middle of the 20th century. Greater regulation of ethical concerns has not necessarily made the research planning process any easier for researchers. Most problematic from an ethics perspective is Lubet’s discussion of Goffman’s role in the commission of a crime. The British Society of Criminology Statement of Ethics says that researchers should be mindful of child protection issues and be prepared for any instances of abuse disclosure.