Basal plasma glucagon (IRG), insulin (IRI) and glucose levels were measured in normal weight (Body Mass Index (BMI) < 30) and obese (BMI < 30) non‐diabetic and diabetic Micronesians (n= 30) on Nauru Island. This population has a high prevalence of diabetes mellitus. IRG levels were significantly higher (P < 0.02) in the non‐diabetic obese, compared to the non‐diabetic lean subjects (109 ± 19 vs 44 ± 12 SEM pg/ml, respectively) and there was a significant positive correlation between basal IRG and BMI (r= 0.79, P < 0·001). IRG levels were similar in diabetic obese and diabetic lean subjects. The pathophysiological significance of the hyperglucagonaemia in these obese subjects is not known, although it may be related to the frequent development of diabetes in this unique population.