Background: The aim of this study was to assess the role of cardiac and vascular parameters as all-cause mortality determinants in patients suffering from gynecological cancers. Methods: This was an observational, prospective, non-randomized, and non-controlled study. Forty-seven consecutive patients (mean age: 58 ± 13 years) were enrolled after cancer staging. All patients underwent evaluation of vascular (common carotid intima-media thickness (mean C-IMT), flow-mediated dilation of the brachial artery (FMD), and antero-posterior diameter of the infrarenal abdominal aorta (APAO)) and cardiac function and morphology before cancer-related interventions. A 6-year follow-up was carried out to assess the overall survival of the whole population. Results: Twenty patients (42%) died by the time of the 6-year follow-up. The brachial artery FMD values were higher in the survivors than the non-survivors (9.71 ± 3.53% vs. 6.13 ± 2.62%, p < 0.001), as well as the LVEF (60.8 ± 3.0% vs. 57.8 ± 4.4%, p = 0.009). There were no differences in the mean C-IMT, APAO, and other echocardiographic parameters. ROC curve analysis identified a baseline LVEF < 57% and FMD value < 5.8% as the best cut-offs. Kaplan–Meier evaluation showed that the LVEF, tricuspid annular plane systolic excursion, and FMD were the best predictors of all-cause mortality, although only the LVEF and FMD were confirmed in multivariate Cox regression analysis. Conclusions: The LVEF and brachial artery FMD are independent prognostic determinants in patients with gynecological cancers.