||During October 1996, the first census of the new South Africa was conducted. Every person present in South Africa on census night (9-10 October) should, in principle, have been enumerated on a census questionnaire between 10 and 31 October. However, it is inevitable that some people will, in practice, not be reached by any census. In a regionally diverse, unevenly skilled, ethnically heterogeneous country like South Africa, and with a degree of political suspicion towards the new government in different areas or among different groups, the proportions of people not enumerated will vary in intricate ways. The challenges were heightened in Census ’96 by the short time (slightly more than a year) available for planning and implementation of the fieldwork. The post-enumeration survey (PES) was conducted immediately after the census on a countrywide basis to measure the proportion of the population not reached in Census ’96. This was the first time that a post-enumeration survey of this scope and nature was conducted in South Africa. This report details the methodology of the PES, notes some of the problems encountered and how they were addressed, and presents the estimates of undercount.