Abstract The tissue composition of the mechanically deboned pork produced by a discontinuous pressure system was investigated. By means of quantitative microscopy volume ratios (in terms of volume in volume fractions) of striated muscle, collagenous and elastic connective tissue, bone and cartilage in homogenized samples from eight different producers were determined. Crude protein, fat, calcium and the hard bone residue were determined chemically. In addition, we measured the size of the hard bone particles. The muscle/connective tissue ratio varied from 0·3 to 6·9. The hard bone residue, determined by means of the KOH-method, varied from 0·05 to 0·62%. 0·6% of the bone particles were larger than 3 mm. In addition to chemical analysis we regard quantitative microscopy for the determination of the tissue composition of mechanically deboned pork as imperative for quality control.