This study aimed to investigate the concordance of different nutritional assessment methods and the prevalence of inadequate nutritional status in newly diagnosed Colorectal cancer (CRC) patients. Cross sectional study was conducted in a public hospital in Alagoas, Brazil. Clinical, nutritional (patient-generated subjective global assessment [PG-SGA], body mass index [BMI], arm circumference [AC], triceps skinfold [TSF], arm muscle circumference [AMC]) and functional (handgrip strength [HGS]) data were collected from July 2017-January 2019. Of the 31 CRC patients with a mean age of 58.97 ± 14.96 years, 48.4% were elderly and 51.6% were female. TSF adequacy (80.8%) and PG-SGA (80.0%) revealed the highest prevalence of malnutrition. BMI identified the same prevalence of malnutrition and excess weight (30.0%). The concordance between PG-SGA and BMI (kappa = 0.086; p = 0.426) was slight, with fair HGS (kappa = 0.268; p = 0.124). PG-SGA and AC (kappa = 0.015; p = 0.99), TSF (kappa = 0.195; p = 0.558) and AMC adequacy (kappa = 0.142; p = 0.380) were poor. PG-SGA can diagnose malnutrition, even in those who are eutrophic/overweight, by other methods. Various methods do not show concordance with PG-SGA, confirming the need for both objective and subjective methods for better diagnosis of CRC patients.