Objectives: Vulvar cancer is a rare gynecologic malignancy. The majority of patients present with early-stage disease and undergo standard surgical treatment, which includes either a simple or radical vulvectomy. The main goal of surgical treatment was to obtain clear margins. This study aimed to investigate pathologic prognostic factors associated with overall survival among patients with stage IB squamous cell carcinoma (SCC) of the vulva. Methods: The National Cancer Database was accessed to identify patients diagnosed with stage IB squamous cell carcinoma of the vulva between 2010-2015. Patients who underwent surgical excision and lymphadenectomy and had at least one month of follow-up were included. Those with complete pathological data (tumor grade, tumor size, presence of lymph-vascular invasion [LVSI], and surgical margin status) were selected for further analysis. Overall survival was evaluated with Kaplan-Meier curves, and univariate analysis was performed with the log-rank test. A Cox model was constructed to control for a priori selected confounders. Results: A total of 2,656 patients with a median age of 63 years were identified. Most patients had tumors < 2 cm (n=1168, 44%), while 35% (n=930) and 21% (n=558) had tumors 2-3.9 cm and ≥4 cm, respectively. Rate of positive margins and LVSI were 7.7% (n=204) and 8.9% (n=237). Almost half of all patients (52%, n=1383) had grade 2 tumors, while 34.7% (n=921) and 13.3% (n=352) had grade 1 and grade 3 tumors, respectively. The 4-year OS rate of the present cohort was 80.9% with a median OS of 93.24 months. By univariate analysis, tumor size (p<0.001; 4-yr OS rates: 87.2% for <2 cm, 78% for 2-3.9 cm, and 72.9% for >4 cm), grade (p=0.006; 4-yr OS rates: 83.3% for grade 1, 80.3% for grade 2 and 77.1% for grade 3) and presence of LVSI (p<0.001; 4-year OS rate: 69.2% vs 82%) were associated with OS. After controlling for patient age, race, insurance status and presence of comorbid conditions, LVSI (HR: 1.61, 95% CI: 1.22-2.12), grade 3 (HR: 1.45, 95% CI: 1.09-1.94), and size >4 cm (HR: 1.91, 95% CI: 1.49-2.45) or 2-4 cm (HR: 1.64, 95% CI: 1.31-2.06) but not positive margins (HR: 1.20, 95% CI: 0.87-1.67) were associated with worse overall survival. In the present cohort, radiation therapy was rarely administered (7.8%, n=207). In a group of patients who had at least one risk factor (grade 3, LVSI or size >4 cm), those who received radiation therapy (n=123) did not have better survival compared to those who did not (n=848, p=0.21); 4-year OS rates were 74.1% and 75.1%, respectively. Conclusions: In a large cohort of patients with stage IB SCC of the vulva, surgical margins status was not associated with overall survival. However, large tumor size, presence of LVSI, and grade 3 tumors were identified as independent negative prognostic factors. Further research is greatly warranted to identify patients who may benefit from adjuvant treatment. Objectives: Vulvar cancer is a rare gynecologic malignancy. The majority of patients present with early-stage disease and undergo standard surgical treatment, which includes either a simple or radical vulvectomy. The main goal of surgical treatment was to obtain clear margins. This study aimed to investigate pathologic prognostic factors associated with overall survival among patients with stage IB squamous cell carcinoma (SCC) of the vulva. Methods: The National Cancer Database was accessed to identify patients diagnosed with stage IB squamous cell carcinoma of the vulva between 2010-2015. Patients who underwent surgical excision and lymphadenectomy and had at least one month of follow-up were included. Those with complete pathological data (tumor grade, tumor size, presence of lymph-vascular invasion [LVSI], and surgical margin status) were selected for further analysis. Overall survival was evaluated with Kaplan-Meier curves, and univariate analysis was performed with the log-rank test. A Cox model was constructed to control for a priori selected confounders. Results: A total of 2,656 patients with a median age of 63 years were identified. Most patients had tumors < 2 cm (n=1168, 44%), while 35% (n=930) and 21% (n=558) had tumors 2-3.9 cm and ≥4 cm, respectively. Rate of positive margins and LVSI were 7.7% (n=204) and 8.9% (n=237). Almost half of all patients (52%, n=1383) had grade 2 tumors, while 34.7% (n=921) and 13.3% (n=352) had grade 1 and grade 3 tumors, respectively. The 4-year OS rate of the present cohort was 80.9% with a median OS of 93.24 months. By univariate analysis, tumor size (p<0.001; 4-yr OS rates: 87.2% for <2 cm, 78% for 2-3.9 cm, and 72.9% for >4 cm), grade (p=0.006; 4-yr OS rates: 83.3% for grade 1, 80.3% for grade 2 and 77.1% for grade 3) and presence of LVSI (p<0.001; 4-year OS rate: 69.2% vs 82%) were associated with OS. After controlling for patient age, race, insurance status and presence of comorbid conditions, LVSI (HR: 1.61, 95% CI: 1.22-2.12), grade 3 (HR: 1.45, 95% CI: 1.09-1.94), and size >4 cm (HR: 1.91, 95% CI: 1.49-2.45) or 2-4 cm (HR: 1.64, 95% CI: 1.31-2.06) but not positive margins (HR: 1.20, 95% CI: 0.87-1.67) were associated with worse overall survival. In the present cohort, radiation therapy was rarely administered (7.8%, n=207). In a group of patients who had at least one risk factor (grade 3, LVSI or size >4 cm), those who received radiation therapy (n=123) did not have better survival compared to those who did not (n=848, p=0.21); 4-year OS rates were 74.1% and 75.1%, respectively. Conclusions: In a large cohort of patients with stage IB SCC of the vulva, surgical margins status was not associated with overall survival. However, large tumor size, presence of LVSI, and grade 3 tumors were identified as independent negative prognostic factors. Further research is greatly warranted to identify patients who may benefit from adjuvant treatment.