The interaction of lead and calcium assimilation was examined in the soft tissues, shell and faeces of the soft tissues, shell and faeces of the garden snail an induced calcium stress, shell wounding. This is known to mobilise Ca both from the shell and soft tissues, conditions which are likely to affect Pb assimilation by each component Following wounding, snails were fed an artificial diet for 7 days with some combination of Pb and/or Ca and Mg in a 22 factorial experiment Dietary Pb raised the concentration of this metal in all tissue components, though the scale of the increase was the same in both wounded and unwoun- ded snails. The smallest increase was in the shell. Ca and Mg levels in the hepatopancreas remain unchanged by the dietary levels of any treatment, but were raised in the rest of the soft tissues. Significantly, the high Pb diet is almost equally effective as wounding in lowering the Ca in this component. Injuring the shell had little effect on the uptake of Pb by the snails.