This paper presents the practical application of a Lean Manufacturing tool - value stream mapping (VSM) - to warehouse processes in a company in the furniture industry. The aim of the article is to identify losses, improve material flow and align staffing with actual operational needs. The current state of the processes in the warehouse responsible for supplying leather and fabric to production was analysed. Detailed measurements made it possible to classify activities as VA, NVA and NNVA. The results showed, among other things, over-communication, misallocation of staff and the presence of redundant posts. Based on the data, current and future state maps were developed for two main materials: leather and fabric. Improvement actions were proposed including staff reductions, better organisation of warehouse space and implementation of Lean tools. Once the changes were implemented, an analysis of the effects was carried out, which confirmed an increase in efficiency and a reduction in waste. The conclusions of the study confirm that VSM is an effective tool to support process improvement not only in production, but also in internal logistics. The article is an example of combining academic knowledge with industrial practice and can be an inspiration for companies looking for improvements in the area of warehousing.