This document is a literature review that analyzes 51 articles on training needs assessment (TNA). The review finds that: 1) There is little agreement on how to measure training needs and most current TNA models are reactive rather than proactive. 2) TNA research and practice lacks theoretical definitions and frameworks and there is little focus on building TNA theories. 3) Studies often focus only on individual roles rather than internal/external contextual factors that influence needs. Based on these findings, the review recommends that future TNA research and practice: 1) Be based on measurable competency gaps at multiple levels of analysis. 2) Consider broader contextual factors that could impact future needs