Objectives This study seeks to evaluate assessment of geriatric frailty and nutritional status in predicting postoperative mortality in gastric cancer surgery. Methods Preoperatively, patients operated for gastric adenocarcinoma underwent assessment of Groningen Frailty Indicator (GFI) and Short Nutritional Assessment Questionnaire (SNAQ). We studied retrospectively whether these scores were associated with in-hospital mortality. Results From 2005 to September 2012 180 patients underwent surgery with an overall mortality of 8.3 %. Patients with a GFI ≥ 3 ( n  = 30, 24 %) had a mortality rate of 23.3 % versus 5.2 % in the lower GFI group (OR 4.0, 95%CI 1.1–14.1, P  = 0.03). For patients who underwent surgery with curative intent ( n  = 125), this was 27.3 % for patients with GFI ≥ 3 ( n  = 22, 18 %) versus 5.7 % with GFI < 3 (OR 4.6, 95 % CI 1.0–20.9, P  = 0.05). SNAQ ≥ 1 ( n  = 98, 61 %) was associated with a mortality rate of 13.3 % versus 3.2 % in patients with SNAQ = 0 (OR 5.1, 95 % CI 1.1–23.8, P  = 0.04). Given odds ratios are corrected in multivariate analyses for age, neoadjuvant chemotherapy, type of surgery, tumor stage and ASA classification. Conclusions This study shows a significant relationship between gastric cancer surgical mortality and geriatric frailty as well as nutritional status using a simple questionnaire. This may have implications in preoperative decision making in selecting patients who optimally benefit from surgery.