This study investigated first-line managers’ experience of and responses to a concise leadership intervention to facilitate the implementation of oral care clinical practice guidelines (CPGs) in nursing homes. Leadership is known to be an important element in knowledge implementation but little is known as to what supports managers to facilitate the process. By means of a process evaluation with mixed methods, the context and a three-month leadership program was explored, including activities during and in relation to the program, and the effects in terms of oral care CPG implementation plans. While the managers appreciated the intervention and considered improved oral care to be a priority, their implementation plans mainly focused the dissemination of an oral care checklist. The findings suggest that extended implementation interventions engaging both managers and clinical staff are needed, and that a concise intervention does not facilitate first-line managers to adopt behaviors known to facilitate knowledge implementation.