In recent years the development and dissemination of logistics knowledge have caused that companies have realized the need to optimize the processes related to the movement and accumulation of goods in the supply chain. On the one hand, financial aspects force companies to reduce inventory levels, on the other, the same companies, aiming at maintaining the continuity of production, must ensure safe inventory level of spare parts even for many years. The objective of this article is to demonstrate the selected issues of spare parts inventory management and to identify the criteria of selection of safety stock on the basis of the survey conducted among Polish manufacturing companies.