Insulin-like growth factor-II mRNA-binding protein-3 (IMP3) is an important factor in carcinogenesis, although its clinical significance in esophageal squamous cell carcinoma (ESCC) remains unknown. The present study investigated the associations between IMP3 expression and the clinicopathological parameters. IMP3 expression was assessed in 191 resected ESCC specimens, and the associations between IMP3 expression in ESCC, the clinicopathological parameters and patient prognosis were examined. Using immunohistochemistry, 113 (59.2%) tumors were identified as IMP3-positive. IMP3 positivity correlated significantly with high pathological (p)Stage, pT stage and pN stage. The IMP3-positive patients exhibited a poorer prognosis compared with the IMP3-negative patients. In univariate analyses, histology [hazard ratio (HR), 1.94; 95% confidence interval (CI), 1.18–3.49; P=0.0082], pT (HR, 2.34; 95% CI, 1.55–3.62; P<0.0001), pN (HR, 2.85; 95% CI, 1.81–4.69; P<0.0001), lymphatic invasion (HR, 2.08; 95% CI, 1.26–3.70; P=0.0036), venous invasion (HR, 1.79; 95% CI, 1.21–2.64; P=0.0039), neoadjuvant chemotherapy (NAC) (HR, 2.01; 95% CI, 1.35–3.00; P=0.0005) and IMP3 expression (HR, 2.12; 95% CI, 1.40–3.29; P=0.0003) were significantly associated with overall survival. Using multivariate analyses, histology (HR, 1.87; 95% CI, 1.13–3.29; P=0.014), pN (HR, 2.19; 95% CI, 1.36–3.66; P=0.0010), NAC (HR, 1.88; 95% CI, 1.24–2.86; P=0.0028) and IMP3 expression (HR, 1.84; 95% CI, 1.18–2.93; P=0.0064) were significant prognostic factors. IMP3 may therefore be a prognostic factor for patients with ESCC who have undergone a curative resection.