The computerised records of all the lambs slaughtered at one plant from August 1991 to July 1992 were used to determine the mortality rate throughout the year and to examine the variables that could have been associated with changes in the mortality rate. The plant processed 3.3 per cent of all the lambs that were slaughtered in the United Kingdom during the period. Lambs arriving for slaughter from a livestock auction were over four times more likely to die in lairage, or to have died during transport, than lambs which were sent directly from the farm. However, the overall mortality rate was only 0.0182 per cent and lower than that for other species for which figures were available. Changes in the mortality rate of the lambs from livestock auctions appeared to be associated with the price of slaughter lambs, and periods of increased mortality coincided with increased rates of carcase condemnations due to 'arthritis', 'abscess' and 'pleurisy'.