Objective: People who spend a longer time walking have lower demands for medical care. However, in view of their longer life expectancy, it is unclear whether their lifetime medical expenditure increases or decreases. The present study examined the association between time spent walking, life expectancy and lifetime medical expenditure. Method: The authors followed up 27 738 participants aged 40-79 years and prospectively collected data on their medical expenditure and survival covering a 13-year-period. Participants were classified into those walking <1 and ≥1 h per day. The authors constructed life tables and estimated the life expectancy and lifetime medical expenditure from 40 years of age using estimate of multiadjusted mortality and medical expenditure using a Poisson regression model and linear regression model, respectively. Results: Participants who walked ≥1 h per day have a longer life expectancy from 40 years of age than participants who walked <1 h per day. The multiadjusted life expectancy for those who walked ≥1 h per day was 44.81 years, significantly lower by 1.38 years in men (p=0.0073) in men and 57.78 years in women, non-significantly lower by 1.16 years in women (p=0.2351). In addition to their longer life expectancy, participants who walked ≥1 h per day required a lower lifetime medical expenditure from 40 years of age than participants who walked <1 h per day. The multiadjusted lifetime medical expenditure for those who walked ≥1 h per day was £99 423.6, significantly lower by 7.6% in men (p=0.0048) and £128 161.2, non-significantly lower by 2.7% in women (p=0.2559). Discussion: Increased longevity resulting from a healthier lifestyle does not necessarily translate into an increased amount of medical expenditure throughout life. Encouraging people to walk may extend life expectancy and decrease lifetime medical expenditure, especially for men.