Objectives: This article reports the first science mapping analysis of the social work field, which shows its conceptual structure and scientific evolution. Methods: Science Mapping Analysis Software Tool, a bibliometric science mapping tool based on co-word analysis and h-index, is applied using a sample of 18,794 research articles published from 1930 to 2012 in 25 main social work journals indexed in the Journal Citation Reports of the Web of Science. Results: Published research social work field concentrated in eight main thematic areas: children, social services, health care, violence, women, HIV/AIDS, social workers, and education. HIV/AIDS and violence have recently attracted the interest of the social word scientific community, while the rest are classical thematic areas that still attract the interest and efforts of the researchers. Conclusion: This conceptual and empirical analysis shows how research themes have evolved in social work.