Do we think enough about what we are doing as information literacy (IL) practitioners? The relationship between reflection and IL development is well documented in academic and professional literature, particularly in the context of teaching librarians using reflective activities to enable learners to think critically about their IL abilities. Parallel literature from education and other fields has promoted the concept of the reflective or thinking practitioner. Drawing on literature and theory from various domains, we review the concepts of reflection and reflective practice, and discuss their application and take-up in library and information work, with particular reference to the teaching role of librarians in the context of developments in critical information literacy. Our review suggests that reflective practice is generally recognised as an important dimension of library and information work, but is currently underdeveloped in comparsion with other professions. Using terminology and theory from the pedagogical arena, we contend that critical reflection needs to be elevated to the special status of a "threshold competence" for library and information professionals generally and for IL practitioners in particular. We also argue that our profession needs purpose-designed domain-specific advice and guidance on reflective practice, to support initial and continuing education of library and information workers, and we conclude by identifying areas where further research is required to clarify the role of reflection in library and information research and evaluation, to explore existing approaches to reflection in professional education programs, and test the transferability of reflective methods used in other professional domains.