Pork carcasses (n=119) originating from 3 swine genotypes (NN=non-carriers of the halothane gene, nn=halothane positive and Nn=halothane negative × halothane positive) slaughtered at an average weight of 100kg were allocated to 2 cooling treatments. One carcass side was cooled conventionally at 1°C while the other was spray chilled for 10h followed by conventional chilling, so that the total chilling time approximated 24h. The spray chilling regime consisted of 40 cycles over 10h (15min intervals), with a cycle duration of 60 s. Carcass weight loss during chilling was recorded along with objective measurements of muscle quality. There were no significant genotype × treatment interactions (P > 0.05) indicating that treatment had a similar effect on the carcasses from the 3 genotypes. Spray chilled sides had significantly (P<0.001) lower temperature in the loin (10.4 vs. 11.7°C) and ham (18.9 vs. 20.4°C) at 6h postmortem and a much reduced carcass shrink (5.6g/kg vs. 26.0g/kg) at 24h compared to conventionally chilled sides. Pork from spray chilled carcasses had similar colour, expressible juice, protein solubility and drip losses to conventionally chilled carcasses, but did have significantly higher (P<0.01) shear force values (6.62 vs. 6.30kg). Primal cuts were a significantly higher (P<0.01) proportion of warm carcass weight in spray chilled, compared to conventionally chilled sides, but this increased yield of cuts was largely attributed to increased proportions of subcutaneous fat and skin. It was concluded that spray chilling substantially decreased carcass shrink during cooling, and had a minor effect on pork muscle quality.