Oral administration of cadmium results in the induction of metallothionein in liver of rhesus monkeys subjected to protein calorie malnutrition and calcium deficiency. Metallothionein was resolved into three iso-proteins viz. MTa, MTb & MTc which varied in their quantities and metal composition in these nutritional stress conditions. 'MTc' was the major iso-protein in protein calorie malnourished monkeys, while 'MTb' predominated in the calcium deficient group.