Nepal has long since been known as a multi-lingual and multi-ethnic country. However, the size of various caste/ethnic groups in the total population was hardly known. Foundation of statistical work started when population counting in Nepal began in 1911 A.D. but it was only a head counting process. The census collected a number of socio-economic attributes such as the mother-tongue of people. The process since then has continued every ten years. Until 1981, there was not a single item in the census schedule enquiring about the caste and/or ethnicity of people of the country. The census of 1991 made an attempt to assess the size of 60 caste/ethnic groups, recorded caste/ethnicity of 18.5 million people of Nepal. Taking account the complex composition of the population in terms of caste/ethnicity and the construction of such a comprehensive list, the possibility of marginal error in recording and grouping them in the census, however cannot be ruled out.
