Background: Disability is a complex concept involving physical impairment, activity limitation, and participation restriction. The Washington Group developed a set of questions on six functional domains (seeing, hearing, walking, remembering, self-care, and communicating) to allow collection of comparable data on disability. We aimed to improve understanding of prevalence and correlates of disability in the low-income setting of Malawi. Methods: This study is nested in the Karonga Health and Demographic Surveillance Site in Malawi; the Washington Group questions were added to the annual survey in 2014. We used cross-sectional data from the 2014 survey to estimate the current prevalence of disability, simulate disability prevalence over the previous 12 years, and examine associations of disability with certain chronic diseases. We then reviewed the consistency of responses to the questions over time using data from the 2015 survey. Results: Of 10,863 participants, 9.6% (95% CI 9.0-10.1%) reported disability in at least one domain. Prevalence was higher among women and increased with age. Since 2004, we estimate the number of people experiencing disability has increased 1.5 times. Obesity and diabetes were associated with disability, but hypertension and HIV were not. Participants reporting “no difficulty” or “can’t do at all” for any domain were likely to report the same status one year later, whereas there was considerable movement between people describing “some difficulty” and “a lot of difficulty”. Conclusions: Disability prevalence is high and likely to increase over time. Further research into the needs of this population is crucial to ensure inclusive policies are created and sustainable development goals are met.