Objectives The extent to which aspects of sleep affect well-being in the long-term remains unclear. This longitudinal study examines the association between chronic insomnia symptoms, recurrent sleep duration and well-being at older ages.

Setting A prospective cohort of UK civil servants (the Whitehall II study).

Participants 4491 women and men (25.2% women) with sleep measured 3 times over 10 years and well-being once at age 55–79 years. Insomnia symptoms and sleep duration were assessed through self-reports in 1997–1999, 2003–2004 and 2007–2009.

Primary outcome measures Indicators of well-being, measured in 2007–2009, were the Control, Autonomy, Self-realisation and Pleasure measure (CASP-19) of overall well-being (range 0–57) and the physical and mental well-being component scores (range 0–100) of the Short Form Health Survey (SF-36).

Results In maximally adjusted analyses, chronic insomnia symptoms were associated with poorer overall well-being (difference between insomnia at 3 assessments vs none −7.0 (SE=0.4) p<0.001), mental well-being (difference −6.9 (SE=0.4), p<0.001) and physical well-being (difference −2.8 (SE=0.4), p<0.001) independently of the other sleep measures. There was a suggestion of a dose–response pattern in these associations. In addition, recurrent short sleep (difference between ≤5 h sleep reported at 3 assessments vs none −1.7 (SE=0.7), p<0.05) and recurrent long sleep (difference between >9 h reported at 2 or 3 assessments vs none −3.5 (SE=0.9), p<0.001) were associated with poorer physical well-being.

Conclusions We conclude that in older people, chronic insomnia symptoms are negatively associated with all aspects of well-being, whereas recurrent long and short sleep is only associated with reduced physical well-being.