Previous research has established that the successful transfer of training content into daily work life depends both on the trainees' individual characteristics and the characteristics of their work team. Specifically, multiple meta-analyses and reviews have confirmed that individuals' openness to experience, agreeableness, and neuroticism, as well as cohesion and transfer climate within the team, influence training transfer. The present study is the first to operationalise and measure both individual and team characteristics in the same sample with a longitudinal study design, enabling a comparison. Training transfer was operationalised as changes in psychological strain following an intervention. Using multilevel analysis techniques with a sample of 275 nurses, individual personality characteristics were not found to influence training transfer, but team cohesion and team members' mean-level conscientiousness did. However, these influences were not in the expected direction. This can be partially explained by the pattern of longitudinal development in the data, in which individuals with higher initial values on psychological strain experienced greater improvement; however, some aspects of the results remained unexplained. Generally, the results suggest that team characteristics are more important than individual characteristics for training transfer. Theoretical and practical implications for future studies are discussed.