This paper makes an attempt to study the magnitude of big units in the non-manufacturing sector of the Indian economy based on data generated by the Economic Census 1998. It also analyses the distribution of big units by industry, state and union territory. It has been demonstrated that the number of big units is small as compared to the total number of units in the country, but that their share in total number of workers is quite substantial, and their share in GDP is likely to be even larger. Accordingly, it has been suggested that the scope of the ASI should be enlarged to cover all such big units in the non-manufacturing sector. This would improve the database for the entire non-agricultural sector, in general, and for national income, in particular.