Zinc and copper deficiency has increasingly been observed in recent years in several field crops growing on calcerous soils of Pakistan. It is possible that soils deficient in one element and receiving it as fertilizer may contain marginal contents of the other. In such cases, application of one element may provide only a limited benefit to the crop or in certain cases may even prove harmful due to the well known Zn-Cu antagonism in their uptake by crops. The present studies were conducted on two alkaline calcareous soils of the Punjab to investigate the effect of Zn and Cu additions on the soil availability of each other.