Rationale: This study determined if there is a significant association between phase angle (PhA), determined by BIA and nutritional risk determined by Nutritional Risk Screening (NRS-2002), Subjective Global Assessment (SGA), hospital length of stay (LOS) and 30 day nonsurvival in adults patients at hospital admission compared to healthy controls. Methods: PhA was determined in patients (n = 983, age 52.7±21.5 yrs, M/F 520/463) and compared to healthy age-, sexand height-matched control subjects from our data base (n = 983, age 52.8±21.7 yrs). Phase angle was determined by 50 kHz tetrapolar skin BIA at hospital admission, prior to treatment. Low PhA was set at 20 days: RR 6.9, CI 5.1 9.1 and LOS 5 20 days: RR 5.2, CI 3.9 6.9 and non-survivors: RR 3.1, CI 2.1 3.4 compared to survivors. Conclusion: Patients at hospital admission had significantly lower PhA than healthy controls. There is a significant association between low PhA and nutritional risk, LOS and non-survival. Thus PhA, which does not require measurement of body height or weight, is an indicator of nutritional risk status that can be used to evaluate nutritional risk in patients at hospital admission.