Background: Authorship, expressly premier positions (first, corresponding, or senior author), in peer reviewed journals is widely acknowledged as scientific credit in academia. Yet, gender inequities and biases pervade this facet of the scientific ecosystem. We reviewed the authorship of pivotal FDA trials that established the standards of care in oncology over the past decade with the goal of defining the magnitude of gender disparity in the most influential literature of the field in recent years. Methods: We collected and assessed data from the primary publication of 231 trials that enabled FDA drug approvals in hematology and oncology from July 2008 to June 2018. Author gender was assigned from listed names using statistical probability and confirmed using institutional websites and online databases (genderchecker database, biographical paragraphs, and social media). Authors where gender was not clearly identified (1.23%) were excluded. To account for equal authorship contribution, we included co-authors as distinct data points, and credit was given to reports for any women in premier authorship positions (first, corresponding, or senior author) to avoid overestimating disparity. Descriptive statistics were used, and 95% confidence intervals (95%CI) were reported using modified Wald method. Proportions were compared using Fisher-exact and Chi-squared test. Unadjusted P values of < 0.05 were considered significant. Results: A total of 4664 (98.8%) authors were included in this analysis across 227 publications. Of these, 1287 (27.6%) were female with a median of 25.9% female authorship in total per trial. Female authorship was significantly higher for non-randomized (30.4% v 26.5% for randomized, P = 0.007) and phase 1/2 trials (29.9% v 26.3% for phase 3, P = 0.009) and varied with trial size (P < 0.001), with the proportion greater in trials with ≤100 patients versus those with > 500 patients. Female authorship in fields of breast and gynecological oncology was higher (41.3%) than other cancers (26.0%, P < 0.001). Women were proportionally less likely to hold premier (9.2% v 18.2%, OR 0.46, 95%CI: 0.4 – 0.6, P < 0.001), first (3.2% v 6.3%, OR 0.49, 95%CI: 0.3 – 0.7, P < 0.001), senior (3.3% v 6.0%, OR 0.54, 95%CI: 0.4 – 0.8, P = 0.002) and corresponding (2.5% v 5.8%, OR 0.42, 95%CI 0.3 – 0.6, P < 0.001) authorship but not second author role (4.1% v 5.1%, OR 0.80, 95%CI 0.6 – 1.1, P = 0.17). Conclusions: The under-representation of women in premier authorship positions in pivotal clinical trials, demonstrated in our study, serves as a barometer of a biased academic infrastructure, amplifying existing calls to address barriers that limit the full inclusion of women in oncology.