We aimed to describe temporal trends in the prevalence and characteristics of hypouricaemia. We analysed medical check-up and administrative claims data to calculate hypouricaemia prevalence from 2009 to 2019. Then, using data from 2018 to 2019, we compared the characteristics of individuals with and without hypouricaemia. We also compared the characteristics of those with lower (serum uric acid [sUA] ≤ 1.0 mg/dL) and higher (1.0 mg/dL < sUA ≤ 2.0 mg/dL) hypouricaemia. In total, 1,600,290 subjects underwent medical check-ups. The age-adjusted prevalence of hypouricaemia remained stable at 0.2% overall (men, 0.1%; women, 0.4%). We identified 1704 subjects with hypouricaemia (598 men and 1106 women) among 796,508 subjects and studied their characteristics. The proportion of most pre-existing diseases, including urinary stones, was lower in those with hypouricaemia than in those without hypouricaemia. Cardio-metabolic diseases and Parkinson's disease were more frequent in men with hypouricaemia than those without hypouricaemia. Women with hypouricaemia tended to have healthier characteristics. Hypertension and dyslipidaemia were more common in the lower hypouricaemia group than in the higher hypouricaemia group. The age-adjusted prevalence of hypouricaemia remained stable over 10 years. The characteristics of hypouricaemia subjects appear to differ between the sexes and between lower and higher hypouricaemia groups. Key Points • The prevalence of hypouricaemia remained almost unchanged over 10 years. • Cardio-metabolic diseases and Parkinson's disease were more frequent in men with hypouricaemia than in those without hypouricaemia. • Subjects with extremely low serum urate (sUA ≤ 1.0 mg/dL) appeared to have higher cardio-metabolic disease risks. • Routine checks of sUA could be useful in screening or predicting these conditions. © 2022. International League of Associations for Rheumatology (ILAR).