This paper presents new estimates of the adult male occupational structure of England and Wales in 1817, over twenty years before the availability of the first reliable returns based upon the census of 1841. The system of baptismal registration introduced by parliament for the Church of England in 1813 required the occupation of the father to be recorded. By collecting these data from every parish register in England and Wales from this year until 1820, it is possible to generate estimates of male occupational structure. Comparison of these estimates with other sources suggests that they are very reliable. Through the use of (1) a population weighting system using the returns from early nineteenth century censuses; (2) the PST system of occupational coding; and (3) a method for attributing the considerable numbers of men described as 'labourer' between the different sectors of employment, the total number of men engaged in each sector of the economy in 1817 can then be estimated.