The aim of this research is to investigate and describe the knowledge transmission dynamic as experienced by senior workers in two public companies. Senior workers usually take up an important role in companies because the years of experience gained at work resulted in the acquisition of knowledge not only related to technical and explicit aspects, but also to a tacit dimension not easily codified and passed on. Taking also into consideration that these workers are close to retirement, their ability to pass on knowledge reflects and determines the capability of the company itself to keep and protect its organizational memory. In order to carry out this research, two case studies based on semi-structured interviews led to the conclusion that throughout the concerned companies’ histories there were discontinued initiatives related to the knowledge transmission process. In addition, the analysis of the interviews’ contents showed the existence of four categories: a) conversion of knowledge: processes, obstacles and enabling conditions, b) relationship between culture and organizational learning, c) perception of seniors towards relations, roles, apprentice’s attitude and learning process, and d) opportunities created by the knowledge acquired. The major difficulty pointed out by the interviewees is connected to the lack of structuring as far as the knowledge management processes are concerned. Therefore, the informal knowledge transmission prevails and, as consequence, each senior worker develops his own teaching methodology.