This paper presents the most often indicated problems with lean practice in industries. The research, which was carried out in a large Polish factory showed that in spite of high assessment of the level of implementation of particular lean tools, the expected effects of waste elimination did not appear. When comparing the results received from the analysis of assumed effects of waste elimination in the factory and the percentage level of implementation of particular tools, it was noticed that the degree of implementation does not influence the elimination of particular types of waste.