Menopause is an important reproductive transition in a woman’s life with implications for concurrent and future health. In the United States one commonly-documented symptom of menopause is sleep disturbance, including insomnia and declines in sleep quality, which can affect mental and physical health. Some studies (e.g the SWAN study) suggest sleep disturbances in menopause vary by race/ethnicity. Whether these differences are due to differences in perception, life conditions or varied nutritional or chemical exposures is unclear. In this grant, we seek to understand menopausal changes in sleep and their role in health outcomes in Mexican women using a mixed methods approach. In particular, we will first evaluate sociodemographic, lifestyle, and environmental predictors of sleep disturbance in a well-characterized epidemiological cohort of peri-menopausal women using survey-based methods. We will compare and contrast these findings with those from ethnographic observations and interviews about menopause and sleep that we will conduct with a subset of women from the same cohort and other peri-menopausal women within their social circles. The ethnographic analyses will provide context for interpreting the epidemiological findings and will also yield novel information about ways that sleep disturbances and other menopausal symptoms are perceived to affect quality of life during this transitional period. These preliminary findings will then be used to inform new survey questions about menopause and sleep that will be applied to the larger cohort (approximately 600 women), as well as inform more focused and intensive ethnographic observations centered on specific aspects of sleep and menopausal health over a period of several months. Ultimately, these findings will be used to inform future grant submissions focusing on the interconnections between sleep, environmental and nutritional factors, and physical and mental health during the menopausal transition in Mexican women.