In this contribution, which builds on and develops a study that was published more than 10 years ago, we address the role of the Chinese Key Labs (KLs) in the international and national scientific arena. We give a short overview of the position of KLs in China, including their budget and manpower. Based on large numbers of Chinese publications obtained from the Web of Science (WoS) and the Chinese Science Citation Database (CSCD), the KLs are compared across publication years to the rest of China (ChRest) with respect to publication output and citation impact. We also look at collaboration in terms of co-publishing between the KLs and the ChRest. As to publications in the WoS, we found that the contribution of KLs compared with the ChRest is slightly and irregularly increasing (using full counting as well as fractional counting), whereas a stronger increasing trend is observed for the corresponding contribution in the CSCD. We observed an increase in the number of collaborations between KLs and Chinese colleagues, regardless of database. For WoS and field normalized citation indicators, we obtained the expected results that researchers at KLs perform considerably better than other Chinese colleagues and, moreover, perform clearly better than database average. As such we may conclude that KLs have lived up to their promise and made real impact on the international arena.