BACKGROUND CONTEXT: Despite recent advances in gender equity in medicine, the representation of women in orthopedic and neurosurgery remains particularly low. Furthermore, compared with their male colleagues, female faculty members are less likely to publish research, limiting opportunities in the academic promotion process. Understanding disparities in research productivity provides insight into the "gender gap" in the spine surgeon workforce. PURPOSE: This study aims to determine the representation and longevity of female physician-investigators among the authors of five spine-related research journals from 1978 to 2016. STUDY DESIGN: This is a retrospective bibliometric review. METHODS: The authors of original research articles from five prominent spine-related journals (European Spine Journal, The Spine Journal, Spine, Journal of Spinal Disorders and Techniques, and Journal of Neurosurgery: Spine) were extracted from PubMed. For authors with a complete first name listed, gender was determined by matching first name using an online database containing 216,286 distinct names across 79 countries and 89 languages. The proportion of female first and senior authors was determined during the time periods 1978 to 1994, 1995 to 1999, 2000 to 2004, 2005 to 2009, and 2010 to 2016. The authors who had their first paper published between 2000 and 2009 were included in additional analyses for publication count and longevity (whether additional articles were published 5 years after first publication). Student t test, chi-square analysis, and Cochran-Armitage trend test were used to determine significance between groups. RESULTS: From 1978 to 2016, 28,882 original research articles were published in the five spine-related journals. A total of 24,334 abstracts (90.9%) had first names listed, identifying 120,723 authors, in total of which 100,286 were successfully matched to a gender. A total of 33,480 unique authors were identified (female authors: 31.8%). Female representation increased for first and senior authors from 6.5% and 4.7% (1978-1994) to 18.5% and 13.6% (2010-2016, p<.001). Growth in female senior author representation declined after 2000 (12.3% vs. 12.9% vs. 13.5% between 2000-2004, 2005-2009, and 2010-2016). Compared with male authors, on average, female authors published fewer articles (mean: 2.1 vs. 3.3, p<.001). Of 15,304 authors who first published during 2000 to 2009, 3,478 authors (22.7%) continued to publish 5 years after their first publication. Female authors were less likely to continue publishing after their first article (15.3% of female authors vs. 24.8%, p<.001). CONCLUSIONS: Female representation in academic spine research has doubled over the past 4 decades, although the growth of female representation as senior author has plateaued. Female physician-investigators are half as likely to continue participating in spine-related research longer than 5 years and on average publish half as many articles as senior author. In addition to recruiting more women into research, efforts should be made to identify and address barriers in research advancement and promotion for female physician-investigators.