Activity-based workplaces have become increasingly prevalent in many organizations. However, research on their implementation regarding perceived productivity within the public sector remains limited. The study’s purpose was to examine differences in perceived productivity, and perceived physical and psychosocial work environment factors, among public sector office employees in activity-based workplaces, in association with the amount of perceived concentration-demanding work. The study was conducted by two surveys responded during the spring 2024 by 450 respectively 320 employees in one Swedish municipality. The results were analyzed by analysis of variance, correlation- and regression analysis. The results indicate that employees with a high amount of perceived concentration-demanding tasks reported lower perceived productivity and experienced poorer perceived physical and psychosocial working environment. Notably, regression analyses revealed that particularly lack of privacy and dissatisfaction with work premises were significantly associated with lower perceived productivity. These findings underscore the importance of considering work task requirements when implementing public sector activity-based workplaces to mitigate potential productivity losses. Further qualitative and quantitative research is needed, particularly those with a longitudinal design, to increase knowledge about how different concentration-demanding work tasks are affected by work in activity-based workplaces.