This study was aimed to observe the effects of progesterone impregnated sponge insertion on milk yield and milk composition in dairy goats. For this reason milk samples were collected before insertion and during the treatment. Sixty four Turkish Saanen goats were used in the research. Animals were milked twice daily. Reduce in milk yield was observed. Fat content of milk decreased, while lactose content, solids-non-fat, density and pH value increased during the sponge application. Protein content was not influenced by the treatment. New experiment under controlled conditions might be planned to characterize the hormonal status of animal and their effects on milk yield and composition.