Both cognitive impairment and malnutrition are common in hemodialysis patients and associated with adverse clinical outcome. The aim of the study was to investigate performance on a detailed cognitive and psychomotor battery in maintenance hemodialysis patients in correlation to nutritional status. A selected population of 65 adult (20 females and 45 males, aged 57.84 ± 12.28 years) hemodialysis (4.78 ± 3.62 years) patients were investigated. The total time of test solving was correlated with Dialysis Malnutrition Score (DMS) in tests of simple visual discrimination of signal location (r = 0.215, P = 0.042), simple convergent visual orientation (r = 0.262, P = 0.020), and convergent thinking (r = 0.244, P = 0.034). The minimum time of test solving was also correlated with DMS in the test of simple convergent visual orientation (r = 0.227, P = 0.038), and in the test of convergent thinking (r = 0.223, P = 0.048). Total ballast, as a descriptor of stability in reaction time, was correlated with DMS in the test of simple visual discrimination of signal location (r = 0.281, P = 0.012), and in a test of short term memory actualization (r = 0.239, P = 0.028). Furthermore, significant correlation was noted between body mass index, serum creatinine, total cholesterol and albumin level with cognitive–psychomotor performance. Hemodialysis patients with a poorer nutritional status performed worse on cognitive and psychomotor tests. Further research is needed to assess the effects of treating malnutrition on cognitive–psychomotor performance in these patients.