The goal of our study was to evaluate the nutritional status of a hemodialysis population through bioimpedance vector analysis (BIVA) and compare the obtained results with conventional clinical laboratory indexes, the validity of which are still a subject of controversy. Eighty adult white hemodialysis patients were enrolled in the study. Their nutritional status was estimated through their body mass index, the percentage deviation of the real body weight to ideal body weight (DeltaP%), Kt/V, normalized protein catabolic rate (nPCR), serum albumin, and BIVA. The incidence of malnutrition was different according to the parameter considered. The logistic regression analysis between the BIVA score and the other nutritional parameters showed that albumin and nPCR can be considered as independent factors able to influence BIVA, with statistical significance. This affects patients with normal values of other nutritional indexes, but fades out when considering patients with low nutritional values. Therefore, nPCR and albumin influence the BIVA determination of the examined population, but this influence affects patients with normal nutritional indexes and disappears when we consider undernourished patients. In conclusion, our results show that hypoalbuminemia, inadequate protein intake, a low Kt/V, a high DeltaP%, or a low body mass index cannot be considered as reliable markers for malnutrition.