The literature has indicated that support of the supervisor is critical for employees to transfer the competences developed during training to their job. However, little is known about which specific supervisor behaviors and attitudes enhance transfer of training. An earlier systematic literature review demonstrated the multidimensionality of supervisor support and discerned 24 categories. The aim of this empirical study is to validate this multidimensional framework and to discover what supervisor support means in practice by exploring how supervisors take up their role in transfer of training. The present study reports on a qualitative study in which 16 supervisors were interviewed about how they experience and display support in training transfer. Findings show that the majority of the 24 categories of specific supervisor support are provided in practice. However, it appears that, particularly, involvement in training selection, coaching learning and transfer, and participation in training characterize the role of the supervisor in transfer of training. The findings furthermore reveal 83 specific approaches, strategies, actions, and attitudes that supervisors report to use to enact each particular category of support for transfer of training.