This thesis is firstly a description of the biochemical estimations of zinc in plasma and serum in health and in various skin diseases. Secondly, it is an attempt to understand the metabolic turnover after the administration of oral radioactive Zinc chloride (Zn65). The introduction to each section gives the background information relative to the investigations reported. After an account of the experiments done, the significance is discussed. Relevant tables and figures are given at the end of each section. In the first chapter, a detailed critical historical review of studies carried out and current status on zinc is presented. The review is not exhaustive. A number of reviews of zinc are available, but each usually places emphasis on a particular aspect of the metal. In addition, certain features of zinc, i. e. place of zinc in dermatological practice remain uncovered. It was, therefore, considered pertinent to compile a general survey and to present some conclusions on those aspects, which have been the subject of much investigation, or which have yielded conflicting results. Chapter II is concerned with the technique used. Estimation of micro-quantities of zinc in human body fluids by using atomic absorption spectrophotometer is a fairly accurate and simple, and standard method. Therefore, no attempt has been made to describe the equipment in detail, but a brief account of the procedure and methods used has been mentioned. Chapter III deals with the estimations of zinc in plasma and serum in healthy subjects and in various skin diseases. Estimation of zinc in plasma is a simple and useful test, but it has its own limitations. In this chapter, current status of plasma and serum zinc has been reviewed critically. This is followed by a description of the results together with a discussion of their significance. Alterations of plasma zinc concentration in response to acute and chronic diseases may provide a potential diagnostic, prognostic and even therapeutic lest during various diseases. Chapter IV deals with a wider aspect of zinc metabolism. Metabolic studies using radioactive Zn were carried out, Zn activity was estimated separately in the whole body, plasma, erythrocytes, tissue, urine and faeces. Information is presented concerning the tissue, course of changes in the body after using a tracer, which was able to follow the metabolic pathway of zinc from the time it was administered to the subject until the time it was excreted. The effect of therapy with systemic zinc sulphate on the turnover of Zn65 is assessed. In Chapter V, therapeutic application of oral zinc sulphate in leg ulcers is described in hospitalised and non-hospitalised patients. The value of oral zinc sulphate as an adjuant therapy is recommended in the management of leg ulcers. However, prolonged and repeated courses for recurrent ulceration should be avoided.