In this speech, Robert McNamara examines the background of the world population problem, analyzes its current trends, evaluates the measures available to deal with it, and suggests actions governments and others can take to help solve it. It now appears that significant fertility decline may have begun in developing countries. Data seem to indicate that crude birth rates have fallen over the past two decades by nearly 13%. However, the current rate of decline is too slow for developing countries to avoid reaching stationary populations far in excess of acceptable levels. For every decade of delay in achieving a net reproduction rate of 1.0, the ultimate steady-state world population will be about 15% greater. Governments should seriously consider the factors affecting fertility reduction and try to (1) reduce infant and child mortality rates, (2) expand basic education and increase education of girls and women, (3) increase productivity and job opportunities for rural and poor groups, (4) stress equitable income distribution, and (5) raise the status of women socially, economically, and politically. To satisfy the demand for change in family norms, governments should provide a wide choice of contraceptive techniques and services, improve delivery systems of services, and expand research seeking better techniques and services. (Author/AV)