Non-destructive methods to measure carcass composition avoid destroying the carcass and reduce waste. These methods include dual X-ray absorptiometry (DXA), computed tomography (CT) and nuclear magnetic resonance imaging (MRI). The aim of this study was to assess pig carcass composition using DXA, CT and MRI data and establish relations between them and chemical analysis of the minced carcass. To this end, 48 pigs (barrows and gilts) were fed diets with different concentrations of nitrogen and phosphorus to obtain a wide range of body composition and bone mineralization. Pigs were slaughtered, and both half carcasses of each were scanned with DXA and CT. Right half-carcasses were frozen and scanned with MRI after thawing. Contents of LEAN, FAT and mineralized BONE (except MRI) were obtained from these devices. Left half-carcasses were minced and chemically analyzed to assess their crude protein (PROT), water (WAT), lipid (LIP) and ASH contents. Relations between DXA, CT and MRI and chemical data were determined using Pearson correlations using XLStat software. Correlations between LEAN and PROT or WAT, as well as between FAT and LIP, were extremely strong (0.94-0.99 for DXA, CT and MRI), while those between BONE and ASH were weaker (0.80 for DXA BONE mineral content and 0.45 for CT BONE volume). Although absolute values of the variables differed among the devices, the relations were strong; thus, establishing accurate equivalency equations seems feasible.