This is a manual published by the Committee on Population and Demography of the National Research Council on various technologies for estimating fertility and mortality from incomplete or inadequate data. Since most developing countries do not have adequate census data or continuous vital registration systems demographic estimation is only possible in those countries with indirect estimation techniques. Each technique described in the manual is based on a simplified model of reality i.e. a model of a set of mathematical relations among relevant demographic variables. Each chapter decribes the basic method of estimation assumptions on which it is based the data required for its application the method of application and a sample application of the method to an actual set of data from a developing country. The following methods of estimation are covered: 1) estimation of fertility from information on children ever born; 2) estimation of childhood mortality from information on children ever born and children surviving; 3) estimation of adult survivorship from information on orphanhood and widowhood data; 4) estimation of adult mortality from distribution of deaths by age data; 5) life table data; 6) age distributions used for fertility or mortality estimations; 7) reverse survival information; and 8) successive census age distributions.