Objectives: The rate of venous thromboembolism (VTE) in gynecologic cancer patients undergoing cancer-directed therapy is not well described. The objective of this study was to evaluate the incidence and risk factors for VTE among patients with newly diagnosed and recurrent gynecologic cancer who receive systemic chemotherapy. Methods: This is a single institution longitudinal retrospective cohort study. The primary endpoint of this study was to determine the cumulative incidence of VTE from the time of cancer diagnosis to receipt of outpatient chemotherapy between January 1, 2020, and January 1, 2021. Secondary outcomes included identifying risk factors associated with VTE. Clinical and demographic data were collected, and descriptive statistics were performed. Pearson Chi-square or Fisher’s exact tests were used for categorical variables. Student’s t-tests or the Wilcoxon Rank-Sum tests were used for continuous variables. All statistical tests considered were two-sided, and a p-value of <0.05 was considered significant. Data analyses were performed in R (V 4.0.5 or later). Results: Of the 215 ambulatory gynecologic cancer patients who underwent chemotherapy, 45 (21%) experienced venous thromboembolism at some point during their cancer course. Our cohort included 117 (54%) ovarian, 66 (31%) uterine, 24 (11%) cervical, and eight (4%) vulvovaginal cancers. The timeline for VTE diagnoses was as follows: nine (20%) were diagnosed at the time of cancer diagnosis, 21 (46.7%) while actively getting chemotherapy, seven (15.6%) in the postoperative period, and eight (17.8%) during surveillance. The incidence of VTE during chemotherapy was 9.6% in patients with a new diagnosis and 12.5% in those with recurrence. Prechemotherapy anemia with hemoglobin <10g/dL (p=0.01), thrombocytosis with platelet ≥350,000/μL (p=0.01), albumin level (p=0.042), and more than three prior chemotherapy lines (p=0.003) were significantly associated with risk of embolism. There was a significant association of Khorana score with VTE risk (p=0.039), with higher scores in the VTE group (median: 2) than in the group without VTE (median: 1). Conclusions: In our cohort of gynecologic cancer patients, we found a high overall incidence of VTE, particularly during receipt of chemotherapy. This was true for patients with newly diagnosed and recurrent cancer. As recently recommended by the Society of Gynecologic Oncology, the use of pharmacologic thromboprophylaxis in highrisk cancer patients undergoing chemotherapy should be strongly considered. Objectives: The rate of venous thromboembolism (VTE) in gynecologic cancer patients undergoing cancer-directed therapy is not well described. The objective of this study was to evaluate the incidence and risk factors for VTE among patients with newly diagnosed and recurrent gynecologic cancer who receive systemic chemotherapy. Methods: This is a single institution longitudinal retrospective cohort study. The primary endpoint of this study was to determine the cumulative incidence of VTE from the time of cancer diagnosis to receipt of outpatient chemotherapy between January 1, 2020, and January 1, 2021. Secondary outcomes included identifying risk factors associated with VTE. Clinical and demographic data were collected, and descriptive statistics were performed. Pearson Chi-square or Fisher’s exact tests were used for categorical variables. Student’s t-tests or the Wilcoxon Rank-Sum tests were used for continuous variables. All statistical tests considered were two-sided, and a p-value of <0.05 was considered significant. Data analyses were performed in R (V 4.0.5 or later). Results: Of the 215 ambulatory gynecologic cancer patients who underwent chemotherapy, 45 (21%) experienced venous thromboembolism at some point during their cancer course. Our cohort included 117 (54%) ovarian, 66 (31%) uterine, 24 (11%) cervical, and eight (4%) vulvovaginal cancers. The timeline for VTE diagnoses was as follows: nine (20%) were diagnosed at the time of cancer diagnosis, 21 (46.7%) while actively getting chemotherapy, seven (15.6%) in the postoperative period, and eight (17.8%) during surveillance. The incidence of VTE during chemotherapy was 9.6% in patients with a new diagnosis and 12.5% in those with recurrence. Prechemotherapy anemia with hemoglobin <10g/dL (p=0.01), thrombocytosis with platelet ≥350,000/μL (p=0.01), albumin level (p=0.042), and more than three prior chemotherapy lines (p=0.003) were significantly associated with risk of embolism. There was a significant association of Khorana score with VTE risk (p=0.039), with higher scores in the VTE group (median: 2) than in the group without VTE (median: 1). Conclusions: In our cohort of gynecologic cancer patients, we found a high overall incidence of VTE, particularly during receipt of chemotherapy. This was true for patients with newly diagnosed and recurrent cancer. As recently recommended by the Society of Gynecologic Oncology, the use of pharmacologic thromboprophylaxis in highrisk cancer patients undergoing chemotherapy should be strongly considered.