With the help of a detailed survey, this article aims to examine how effective communication can aid the lean transformation process within a company. Lean methodologies enable companies to create processes and systems that are so efficient that they give them a significant competitive advantage in the marketplace. On the one hand, these improvements can be made by reducing costs and losses and, on the other, by increasing value to the customer. In this study, a survey was carried out in Hungary among 20 Hungarian companies with lean practices, collecting more than 800 employee responses and focusing on the benefits of lean practices in manufacturing companies. Both managers and employees expressed the same opinion, highlighting the importance of communication in the transformation process. The research was conducted among companies with lean experience, and the results and conclusions described can be applied to the lean implementation projects of Hungarian manufacturing companies. Lean practitioners identified communication as almost as important as team composition and management commitment. The research showed that the success of the transformation depends not only on implementing but also on sustaining and remaining dedicated to change, which is only feasible with the right form and frequency of communication.