This manual is intended to serve as a tool for the development, implementation and ongoing improvement of a congenital anomalies surveillance programme, particularly for countries with limited resources. The focus of the manual is on population-based and hospital-based surveillance programmes. Some countries may not find it feasible to begin with the development of a population-based programme. Therefore, the manual covers the methodology needed for the development of both population-based and hospital-based surveillance programmes. Further, although many births in predominantly low - and middle - income countries occur outside of hospitals, some countries with limited resources may choose to start with a hospital-based surveillance programme and expand it later into one that is population based. Any country wishing to expand its current hospital-based programme into a population-based programme, or to begin the initial development of a population-based system, should find this manual helpful in reaching its goal.