Lambs were transported for 24 hours during summer and winter at a range of stocking densities. Shorn lambs of mean liveweight 39.5 kg were transported at densities of 0.448, 0.513, 0.602 and 0.769 m2/100 kg in July and fully-fleeced lambs of 37.3 kg mean liveweight were transported at densities of 0.613, 0.680, 0.775 and 0.909 m2/100 kg in February. Fewer lambs lay down and rested at high stocking densities and there was a marked increase in the plasma levels of creatine kinase at the highest stocking density in winter. All other measured effects of stocking density were small when compared with the overall effects of transport. There was a decrease in body temperature during transport, especially in the lambs that were recently shorn, even though they were transported during warm summer conditions. At the highest stocking density there was a smaller decrease in body temperature.