Objective: We compared the subjective global assessment (SGA) and a range of SGA-based assessment tools with body cell mass (BCM) in patients with stage IV and V predialysis chronic kidney disease (CKD). Study Design: This was a cross-sectional, observational study. Setting: The study took place at a public tertiary hospital predialysis outpatient clinic. Patients: A total of 56 consecutive consenting patients with CKD (61% were male; age [mean ± standard deviation] 70.2 ± 11.6 years; glomerular filtration rate 22.2 ± 6.8 mL/min). Main Outcome Measure: Nutrition status was the main outcome measure. Results: In this population, the prevalence of malnutrition was 19.6% (n = 11, SGA B; no C ratings). Malnutrition was associated with lower BCM (mean BCM, 26.3 vs. 33.4 kg, P = .007, measured by total body potassium), body weight (64.8 vs. 76.1 kg, P = .042), body mass index (23.7 vs. 27.6 kg/m2, P = .015), and greater weight loss over the previous 6 months (-6.2 vs. -0.1 kg, P = .004). BCM had a weak relationship with 7-point SGA (P = .267), malnutrition inflammation score (r = -0.27 P = .063), and patient-generated SGA (r = -0.27 P = .060). There was no association for either measure of nutrition status (SGA or BCM) with albumin, glomerular filtration rate, or C-reactive protein. Conclusion: SGA in its original form most accurately delineated malnutrition by depleted BCM and is the most appropriate tool for cross-sectional assessment of nutrition status in patients with predialysis CKD.