Rationale: It has been shown that early nutrition intervention improves nutrition status (NS) and treatment tolerance in patients with esophageal cancer. However, it remains unknown whether pretreatment parameters of NS are associated with treatment modifications (TMs) during neoadjuvant chemoradiation (CR) in patients who are intensively nutritionally supervised during treatment. Methods:All outpatients with esophageal cancer who were scheduled for CR in the VU medical center from 2006-2015 were included. NS was assessed by body mass index (BMI), weight loss in the past 6 months (WL), fat mass index (FMI) and fat-free mass index (FFMI), handgrip strength (HGS), and energy/protein intake. Logistic regression analyses, adjusted for age, sex, previous tumor, tumor stage, and physical status, were applied. TMs were defined as delay, dose reduction or discontinuation of chemotherapy and/or radiotherapy, hospitalization, or mortality (yes/no). Results: In total, 162 patients were included (73% male; mean age 65 ± 9 years). Mean BMI was 25.1 ± 4.5 kg/m2, and WL was 4.8 ± 5.1 kg. HGS and FFMI were below the 10th percentile of reference values in 21 and 37 patients, respectively. Thirty-five (22%) patients experienced at least 1 TM during CR; unplanned hospitalization (n = 18, 11%) was the most prevalent. After adjustments for confounders, only HGS was statistically significantly associated with TMs (odds ratio, 0.93; 95% confidence interval, 0.88-1.00). Conclusion: In this group of intensively supervised patients with esophageal cancer, pretreatment parameters of NS had little influence on TMs during CR. Only a lower HGS was associated with TMs.