Purpose To determine the prognostic value of sarcopenia measurements done on staging 2-18F FDG PET/CT together with metabolic activity of the tumor in patients with adenocarcinoma esophagogastric cancer with surgical treatment. Methods Patients with early-stage, surgically treated esophageal adenocarcinoma and available pre-treatment 2-18F FDG PET/CT were included. The standard uptake value (SUV) and SUV normalized by lean body mass (SUL) were recorded. Skeletal muscle index (SMI) was measured at the L3 level on the CT component of the PET/CT. Sarcopenia was defined as SMI < 34.4cm 2 /m 2 in women and < 45.4cm 2 /m 2 in men. Results Of the included 145 patients. 30% were sarcopenic at baseline. On the univariable Cox proportional hazards analysis, ECOG, surgical T and N staging, lymphovascular invasion (LVI) positive lymph nodes, and sarcopenia were significant prognostic factors concerning RFS and OS. On multivariable Cox regression analysis, surgical N staging ( p  = 0.025) and sarcopenia ( p  = 0.022) remained significant poor prognostic factors for OS and RFS. Combining the clinical parameters with the imaging-derived nutritional evaluation of the patient but not metabolic parameters of the tumor showed improved predictive ability for OS and RFS. Conclusion Combining the patients’ imaging-derived sarcopenic status with standard clinical data, but not metabolic parameters, offered an overall improved prognostic value concerning OS and RFS.