Purpose: Much research has addressed how to implement lean in a focal company, but little has been published about how to integrate suppliers in strategies and the focal company’s culture, such as lean production or lean thinking. The purpose of the article is to investigate if suppliers can become more integrated in the supply chain by training in lean thinking at the focal company and to explain a possible structure of the training. Design/methodology/approach: A multiple-case study has been conducted of the focal com- pany and five of its supply companies. The findings are supported empirically by on-site interviews and by observations, as well as by a binomial two-proportion test that was used to analyse the statistical data of the delivery precision. Findings: While the training programme does not show a conclusive result for the supply chain, it has made a difference for all participating suppliers. In most cases the training programme was a trigger that started or boosted the internal work with continuous improvements. In some cases it helped create structured ways of working and improved the internal production flows.