The aim was to study time trends in prevalence of disability in ADL and survival among men and women 78 years and older comparing two cohorts. The study was a time trend study based on two population-based community cohorts, the Nordanstig Project (NP), collected 1995–1998 and the Swedish National Study on Aging and Care in Nordanstig (SNAC-N), collected 2001–2003. The participants were people aged 78 years and older from the NP cohort (N = 303) and from the SNAC-N cohort (N = 406). All were clinically examined by physicians and nurses using standardized protocols. Disability was defined as a need for assistance in one or more ADL activities. The prevalence of disability and survival were compared using logistic and Cox models. The prevalence of ADL disability was stable for men, while women became more disabled in ADL during the time period, OR 2.36 (1.12–4.94). There was no significant difference in survival time between the cohorts in either ADL disabled persons or non-disabled persons. There was a tendency for increased survival for non-disabled persons in SNAC-N compared with NP, although not significant; this was particularly true for women. In general, women survived longer than men did regardless of whether they were ADL disabled or not. The time trends for ADL disability found in the study show that ADL disability had increased in women but not in men. More studies are needed to identify risk factors for ADL disability with a view to preventing it in time.