Breast cancer is a major public health concern in the UK, one accounting for 16% of all cancer incidences and 7% of all cancer deaths. Fortunately, the natural history of this malignancy can be beneficially changed through the early detection and treatment of benign and malignant breast disease, which have been enabled by mammographic screening techniques. However, the success of screening programmes depends on their ability to attract the at-risk population, as well as the analytical specificity and sensitivity of the screening test itself. The NHS Breast Screening Programme attracts about three-quarters of the invited population each year. In 2010, all but one region reported a triennial coverage of more than 75%; London was the exception, reporting a regional coverage of 69%. London consistently fails to meet the national target. Missed appointments are a primary cause of inefficiency in health-care delivery, with adverse clinical implications for the non-attending patient and substantial monetary costs to the health service. To ensure the future success of the breast screening programme, development of strategies to improve uptake of hard-to-reach patients is imperative. Research has shown that receiving an appointment reminder by text message has been successful in reducing non-attendance in other areas of health care; the same might be true for breast screening. Our primary aim was to establish whether text message reminders can significantly improve the uptake of breast screening by women on an intention-to-treat basis in the London Borough of Hillingdon. Our secondary aim was to assess whether text message reminders are an effective intervention for improvement of uptake of breast screening by hard-to-reach patients such as women living in deprived areas and women of black and minority ethnic groups.