OBJECTIVE: to assess the association of kidney function with quality-of-life in community-dwelling older adults aged 75 years or more in the UK. DESIGN: cross-sectional study. SETTING: primary care; 12 UK general practices participating in a cluster trial of health screening. SUBJECTS: estimated glomerular filtration rate (eGFR, ml/min/1.73 m(2)) using the four-variable modified diet in renal disease equation was derived in 1,195 men and 1,772 women with available bloods, these were 92% of 3,211 study participants who consented to interviews and 73% of those invited into the original cluster trial of health screening. MAIN OUTCOME MEASURES: interviews by trained fieldworker using the Sickness Impact Profile (home management, mobility, self-care, social interaction), and the Philadelphia Geriatric Morale Scale. Higher scores imply worse quality-of-life in a given domain. RESULTS: in age- and co-morbidity-adjusted analyses there was an association of eGFR <45 and the highest scores (defined as ≥median) of mobility (men: odds ratio (OR) 2.91, 95% confidence interval (CI) 1.56-5.41; women: OR 1.73, 95% CI 1.02-2.94), home management (men: OR 1.49, 95% CI 1.09-2.04; women: OR 3.50, 95% CI 1.18-10.35), social interaction (men: OR 3.34, 95% CI 1.73-6.45; women: 2.64, 95% CI 1.61-4.33) when compared with those with eGFR ≥60 and who reported no problems. Men with eGFR <45 had low morale (OR 2.45, 95% CI 1.02-5.87) but this was not found for women (OR 1.40, 95% CI 0.65-3.04), whereas women (but not men) with eGFR <45 reported problems with body care (women: OR 1.68; 95% CI 1.25-2.27: men: OR 0.89, 95% CI 0.55-1.46). CONCLUSIONS: an eGFR <45 is associated with poorer quality-of-life at older age. More research is needed to identify modifiable causes to improve quality-of-life in older people with such a degree of kidney function impairment.