Each primal cut of a pig carcass has a separate market and value. Commonly the degree of blemishes on the skin of the cut is the main determinant of its quality. However, the lean meat percentage of the primal cut is also of importance, especially to the consumer. If prediction equations were in place to enable processors to more accurately estimate the lean meat percentage of specific primal cuts, it would allow optimisation of primal cuts for specific markets or processing operations. The experiment investigated the accuracy of lean meat prediction equations for primal cuts using indicator cuts, grading probe data, data from photographic images and whole carcass lean meat percentage values.