Academic advising is fraught with ethical dilemmas. Advisors' actions are beholden to various and conflicting constituents. Existing literature on ethics in academic advising provides guidance for advisors via normative ethical principles, suggested processes, and statements about how advising ought to be practiced. However, knowledge of advisors' experiences of ethical dilemmas remains limited. This grounded theory study produced a model of how primary-role academic advisors working in large state university systems engage in ethical practice. It includes four cyclical phases: pre-encounter, encounter, discernment, and response. Each phase highlights discrete but interconnected themes grounded in data gleaned from semi-structured interviews with 12 advisors. The grounded theory has implications for advisors, advising administrators, and future research in bolstering ethical practice.