Background: Malnutrition is an important risk factor for adverse postoperative outcomes such as infection and delayed wound healing, often resulting in longer hospital stay and higher readmission and mortality rates. The aim of this study is to assess the relationship between the risk for malnutrition prior to elective vascular surgery and postoperative complications. Methods: In this observational cross-sectional study, elective vascular surgery patients were included from January 2015 until November 2018. Included were percutaneous, carotid, endovascular, peripheral bypass, abdominal, lower extremity amputation, and other interventions. The patients were assessed for risk for malnutrition using the Patient-Generated Subjective Global Assessment Short Form (PG-SGA SF), whereby <4 points was defined as low risk, 4–8 points as medium risk, and ≥9 points as high risk for malnutrition. Postoperative complications were registered using the Comprehensive Complication Index. Univariate and multivariate analyses were performed to evaluate the relationship between risk for malnutrition and postoperative complications. Results: Of 468 patients, 113 (24.1%) were found to be at risk for malnutrition (PG-SGA SF ≥4 points). Occurrence of postoperative complications (23.9% in the low risk vs. 51.9% in the high risk group, P = 0.006), length of hospital stay (5.5 ± 4.3 days in the low risk vs. 8.2 ± 5.1 in the high risk group, P = 0.005), 30-day readmission (4.7% in the low risk vs. 19.2% in the high risk group, P = 0.009), and Comprehensive Complication Index (median score of 0 in the low risk vs. 8.7 in the high risk group, P = 0.018) varied significantly between the 3 PG-SGA SF groups. After multivariate analysis, the medium risk for malnutrition group had a 1.39 (95% confidence interval 1.05–1.84) times higher Comprehensive Complication Index than the low risk for malnutrition group (P = 0.02). Conclusions: Electively operated vascular surgery patients at risk for malnutrition are more likely to develop postoperative complications. This finding suggests that improving the nutritional status of vascular surgery patients prior to surgery has the potential to reduce the risk of complications.