Women have greater longevity than men and represent a larger proportion of the expanding older population. Several health, disease, behavioral and sociodemographic factors contribute to the higher prevalence of disability in women compared to men. This paper presents a review of methodologic and epidemiologic considerations important to our understanding the gender differences in the prevalence of disability, and discusses underlying causes for these differences. Compared to men, women have a longer duration of life lived with disability, in part due to higher prevalence of non-fatal chronic conditions, constitutional factors such as lower muscle strength and lower bone density, and higher rates of life-style factors such as sedentary behavior and obesity. Several of these factors are modifiable, and provide important targets for researchers, clinicians, and public health practitioners in their efforts to reduce the burden of disability in the older population.