Background and aimsMalnutrition is associated with poor outcomes in patients with chronic diseases. Aim of this study is to investigate the prevalence of malnutrition in patients with hypertension and relationship between malnutrition severity and long-term mortality in these patients. Methods and resultThe study included 11,278 patients with hypertension from the National Health and Nutrition Examination Survey database. The degree of malnutrition was assessed using the Controlled Nutritional Status score, with patients divided into normal, mild, and moderate-to-severe groups. After 10 years of follow-up, the results showed that patients who died had higher CONUT scores, poorer nutritional status, and lower albumin, total cholesterol, and lymphocyte counts than those who survived (P < 0.05). The Kaplan–Meier analysis revealed that patients with poor nutritional status had a significantly higher risk of all-cause death. In the Non-Lipid Lowering Drugs group, the CONUT score (hazard ratio (HR): 1.225; 95% confidence interval (CI): 1.162–1.292; P < 0.0001), as well as mild (HR: 1.532; 95% CI 1.340–1.751; P < 0.0001) and moderate-to-severe malnutrition (HR: 2.797; 95% CI: 1.441–5.428; P = 0.0024), were independent predictors of long-term mortality. The competing risk regression models showed that cardiovascular and cerebrovascular mortality increased with increasing CONUT scores. The results were robust in both subgroup and sensitivity analyses. ConclusionMalnutrition significantly impacts long-term mortality in hypertensive patients. The CONUT score may be a useful tool for assessing the nutritional status of patients with hypertension in the non-lipid-lowering population and for predicting their long-term mortality.