Malnourished patients undergoing esophagectomy have increased risk of postoperative complications. The aim of the current study was to identify nutritional and functional risk factors for postoperative complications in patients with esophageal and gastroesophageal junction cancer who underwent esophagectomy. Seventy patients who were admitted at the First Department of Surgery, Laikon General Hospital, Athens, Greece, were included in this study. Laboratory data and data regarding nutritional and functional status were recorded preoperatively. Postoperative complications were graded according to Clavien-Dindo classification. Thirty-seven patients (52.9%) developed postoperative complications. Albumin and Geriatric Nutritional Risk Index (GNRI) levels were lower in patients who developed major complications compared to patients who did not develop postoperative complications (3.90 ± 0.44 vs 4.18 ± 0.37 g/dL, p = 0.014 and 107.40 ± 15.76 vs 114.98 ± 12.26, p = 0.050 respectively). Major complications were associated with higher percentage of weight loss (12.1 ± 11.1 vs 6.2 ± 7.5%, p = 0.019) and with low handgrip strength (80 vs 16.9%, p = 0.006). Albumin (3.93 ± 0.18 vs 4.15 ± 0.41 g/dL, p = 0.019) and low muscle mass (22.6 vs 2.8%, p = 0.016) were significantly associated with anastomotic leakage occurence. The incorporation of patients' nutritional and functional status in the preoperative risk assessment might increase prognostic ability concerning postoperative complications of patients undergoing esophagectomy.