Most developing countries have compiled national accounts on a regular basis only for the last few years. It has not yet been possible for them to collect many of the statistics necessary to obtain good coverage of their economic activities by methods which would generally be accepted as reliable. Consequently the checks on reliability imposed by the framework of the national accounts are often absent, and the accounts prepared contain many estimates of doubtful quality. These doubts can usually only be removed as statistics collected by better methods become available. This is proving to be a slow process, partly because of the shortage of trained statistical staff and the competing demands of social and demographic statistics and partly because of the inherent difficulties in collecting good statistics from small businesses and traditional households. The need to define traditional households as producers as well as consumers leads to our demanding extra information from this difficult sector. In addition it is often difficult for the national accounts statistician, and even more so for the user, to find out in the time available exactly how some of the statistics with which he is presented were obtained. When this cannot be done it is impossible to assess their reliability. Thus assessing the overall reliability of national accounts in developing countries for even a limited range of uses is at present largely a matter of personal judgment. The information necessary to make more objective assessments rarely exists and hence the problems which developed countries face in using such information are not yet within the experience of most developing countries.