The primary purpose of the current study is to identify how human resource development (HRD) research has contributed to the knowledge base across social science disciplines during the past two decades. We identified the top 20 Academy of Human Resource Development (AHRD) journal articles that have been most frequently cited in research articles published in journals other than the four AHRD journals. With the use of content analysis of the most-cited articles, three key research themes were identified: (a) training transfer and evaluation, (b) learning in organizations, and (c) knowledge sharing and knowledge creation. The research contributions of HRD within the field of HRD and across disciplines are discussed. (Contains 2 tables and 3 figures.)