Abstract
The integration of generative AI into legal practice is advancing rapidly across jurisdictions, including Spain. However, regulatory, ethical and technical challenges require special attention here. This article provides a comprehensive guide to deploying generative AI in law firms and corporate legal departments within the Spanish legal framework. It examines applicable regulations such as the General Data Protection Regulation (GDPR), Spanish Organic Law 3/2018 on Data Protection (LOPDGDD) and the Spanish General Statute of the Legal Profession (Estatuto General de la Abogacía Española). It also explores the ethical and professional duties set out in the Code of Ethics of the Spanish Bar Association in relation to confidentiality, competence and client communication. Furthermore, the article outlines the technical architecture of generative AI systems, including deployment models, data security protocols and integration strategies tailored to legal environments. Finally, the article offers a set of actionable best practices to mitigate the legal, operational and ethical risks associated with using AI in legal services, thereby establishing a robust governance and compliance framework.