This brief summarizes the importance of professional development, identifies core competencies for youth workers, highlights professional development training delivery models, and sets fourth next steps for professional development that can benefit youth programs. Programs often attribute their success to effective youth workers, and research shows that professional development can enhance the skills of both new and longtime staffers. Though the concept of professional development is not new, its significance for youth workers has been gaining momentum slowly. What is professional development and what is the Context of Youth Programs: Professional development has existed for several decades among national youth organizations, but professional development options have become increasingly diverse, reflecting the diverse paths people take to become youth workers. Thus, professional development opportunities for youth workers may include but are not limited to: (1) Higher education training; (2) Pre-service training and orientation for new staff; (3) In-service training provided by programs to current staff; (4) Training seminars and resource centers provided by external organizations; (5) Local and national credentialing systems and programs; (6) Mentoring programs; and (7) Ongoing informal resources, such as newsletters, online discussion boards, and "brown bag" lunches for staff members to share ideas and expertise. This document discusses the importance of professional development for youth workers in relation to: (1) the value of professional development; (2) core competencies for youth workers; (3) professional development training delivery models; and (4) possible next steps, such as first developing a professional development system for workers in one's program, and second, accessing a range of existing professional development opportunities. The document concludes with an "In the Spotlight" piece on the Facilitating Leadership in Youth (FLY) program, located in Washington, DC. (Contains 27 endnotes.)