This contribution seeks to highlight the constraints of knowledge transmission between workers in a Portuguese metalworking company, discussing how can it be built sustainable transmission conditions to promote workers’ health and development. Considering the challenges workers face in daily knowledge transmission, two studies were carried out (with Printing Lithographers and tinplate metalworkers) namely through work analysis and semi-structured interviews, using a multidimensional analysis to reflect on the sustainability of transmission. The results illustrate the permanence of working conditions that intensify work and limit the possibilities of transmission, while issues related to impeded or conditioned autonomy in transmission, discretion in professional paths and lack of action on the part of the HR team and production managers also emerge. Based on the empirical contributions, a proposal for knowledge transmission sustainability is discussed to support reflection and intervention on the conditions of transmission in workplaces.