This guide examines the responsibilities of private sector lawyers in avoiding, addressing, preventing and mitigating adverse human rights impacts on tenure right holders when advising on agricultural investments. These responsibilities arise under international standards for the protection of legitimate tenure rights, including the Voluntary Guidelines on the Responsible Governance of Tenure of Land, Fisheries and Forests in the Context of National Food Security. In light of the United Nations Guiding Principles on Business and Human Rights (UNGP), the guide also considers the dual responsibility of lawyers in this context through the impact of these standards on the professional duties of the lawyer (including in-house counsel) towards the investor client. Moreover, it sheds light on their impact on the law firm's responsibilities as a business in its own right, also according to its corporate social responsibility commitments. The guide concludes with a number of recommendations to law firms to promote compliance with UNGP on behalf both of the investor client and of themselves, including reviewing their internal policies on human rights, and giving specific guidance on due diligence.