This article explores the concept of quality of life. Current understandings of quality of life are considered in relation to the notion of discipline-specificity. The authors contend that different disciplines require distinct definitions of quality of life and that research which informs practitioners about quality of life needs to be discipline-specific and theory-based. The contribution of the human becoming theory to knowledge and understanding of quality of life in nursing science is explored, drawing on insights from theory-guided practice and research.