This study aimed to determine anthropometric cut-points for screening diabetes and metabolic syndrome (MetS) in Arab and South Asian ethnic groups in Kuwait; and to compare the prevalence of MetS based on the ethnic-specific waist circumference (WC) cut-point and the International Diabetes Federation (IDF), and American Heart Association/National Heart, Lung, and Blood Institute (AHA/NHLBI) WC criteria. The national population-based survey dataset of diabetes and obesity in Kuwait adults aged 18-60 years were analysed. Age-adjusted logistic regression and receiver operating characteristic (ROC) analyses were conducted to evaluate for 3589 individuals the utility of WC, waist-to-height ratio (WHtR) and body mass index (BMI) to discriminate both diabetes and ≥3 CVD risk factors. Areas under the ROC curve were similar for WC, WHtR and BMI. In Arab men, WC, WHtR and BMI cut-offs for diabetes were 106 cm, 0.55, and 28 kg/m2; and for ≥3 CVD risk factors, 97cm, 0.55, and 28 kg/m2, respectively. In Arab women, cut-offs for diabetes were 107 cm, 0.65, and 33 kg/m2; and for ≥3 CVD risk factors, 93 cm, 0.60 and 30 kg/m2 respectively. WC cut-offs were higher for South Asian women than men. IDF-based WC cut-offs corresponded to a higher prevalence of MetS across gender and ethnic groups, compared to Kuwait-specific cut-offs. Any of the assessed anthropometric indices can be used in screening of diabetes and ≥3 CVD risk factors in Kuwaiti Arab and Asian populations. ROC values were similar. The WC threshold for screening MetS in Kuwaiti Arabs and South Asians are higher for women.