The aim of this work was to determine the accuracy of the lean meat share (LM) estimate with FOM instrumentation, in pigs. A total of 720 pigs were measured at slaughterhouses. The tests were carried out to determine the ability to measure the same value with repeated injections in the same point of the pig carcass, taking into account the operator, the equipment and the state. Based on the observed measurements it can be stated that the difference between measurements of the muscle and fat in the first and repeated injections is very low. The estimation in the CR, compared to the SR is, for both punctures, higher. As regards repeatability, it is obvious that the pig measuring in the SR is performed more carefully. Also, CR operators, compared to SR, exhibit, in the case of repeated punctures, a greater variability.