There has recently been increased interest in the assessment of body composition in patients with esophageal cancer for the purpose of nutritional evaluation and prognostication. This systematic review and meta-analysis intends to summarize and critically evaluate the current literature concerning the assessment of body composition in patients with esophageal cancer and to assess its potential implication upon early and late outcomes. A systematic literature search (up to August, 2017) was conducted for studies describing the assessment of body composition in patients with esophageal and gastroesophageal junctional cancer. Meta-analysis of postoperative outcomes including long-term survival was performed using random effects models. Twenty-nine studies reported the assessment of body composition in 3193 patients. Methods used to assess body composition in patients with esophageal cancer included computerized tomography (n = 18 studies), bioelectrical impedance analysis (n = 10), and dual-energy X-ray absorptiometry (n = 1). Significant variability was observed in regard to study design and the criteria used to define individual parameters of body composition. Sarcopenic patients had a higher incidence of postoperative pulmonary complications (7 studies, OR 2.03, 95% CI 1.32-3.11, P = 0.001) after esophagectomy. Meta-analysis of six studies presenting long-term outcomes after esophagectomy identified significantly worse survival in patients who were sarcopenic (HR 1.70, 95% CI 1.33- 2.17, P < 0.0001). The assessment of body composition has the potential to become a clinically useful tool that could support decision-making in patients with esophageal cancer. Current evidence is however weakened by inconsistencies in methods of assessing and reporting body composition in this patient group.