This editorial article examines what is meant by sex, gender and equity and argues that these are critical concepts to address in the effective management of communicable disease. Drawing on examples from the three major diseases of poverty (HIV, tuberculosis [TB] and malaria), the article explores how, for women and men, gender and poverty can lead to differences in vulnerability to illness; access to quality preventive and curative measures; and experience of the impact of ill health. This exploration sets the context for the three companion papers which outline how gender and poverty shape responses to the three key diseases of poverty in different geographical settings: HIV/AIDS in Kenya; TB in India; and malaria in Ghana.