Venous thromboembolism (VTE) is a life-threatening haemostatic disease frequently diagnosed among the cancer population. The Khorana Score is currently the primal risk assessment model to stratify oncological patients according to their susceptibility to VTE, however, it displays a limited performance. Meanwhile, intensive research on VTE pathophysiology in the general population has uncovered a range of single-nucleotide polymorphisms (SNPs) associated with the condition. Nonetheless, their predictive ability concerning cancer-associated thrombosis (CAT) is controversial. Cervical cancer (CC) patients undergoing chemoradiotherapy often experience VTE, which negatively affects their survival. Thus, aiming for an improvement in thromboprophylaxis, new thrombotic biomarkers, including SNPs, are currently under investigation. In this study, the predictive capability of haemostatic gene SNPs on CC-related VTE and their prognostic value regardless of VTE were explored. Six SNPs in haemostatic genes were evaluated. A total of 401 CC patients undergoing chemoradiotherapy were enrolled in a retrospective cohort study. The implications for the time to VTE occurrence and overall survival (OS) were assessed. CAT considerably impacted the CC patients' OS (log-rank test, P < 0.001). SERPINE1 rs2070682 (T > C) showed a significant association with the risk of CC-related VTE (CC/CT vs. TT, log-rank test, P = 0.002; C allele, Cox model, hazard ratio (HR) = 6.99 and P = 0.009), while F2 rs1799963 (G > A) demonstrated an important prognostic value regardless of VTE (AA/AG vs. GG, log-rank test, P = 0.020; A allele, Cox model, HR = 2.76 and P = 0.026). For the remaining SNPs, no significant associations were detected. The polymorphisms SERPINE1 rs2070682 and F2 rs1799963 could be valuable tools in clinical decision-making, aiding in thromboprophylaxis and CC management, respectively.