A structured literature review was conducted to understand clinical instructors' perceptions of their role and the factors that facilitate and constrain their teaching in undergraduate nursing programs. The literature published in English between 2000 and 2011 was searched, and data were extracted from 15 articles that met the inclusion criteria. The analysis identified four themes-characteristics of the role, characteristics of effective clinical teaching, influence of the clinical context on the role, and influence of the academic context on the role. Clinical instructors are portrayed as needing to be good educators, as well as excellent clinicians. However, they often lack formal education and professional development opportunities related to the role and must draw on their individual personal and professional experiences to guide their teaching to meet the demands of both the clinical and academic contexts in which they simultaneously work.