The purpose of this study was to identify characteristics that distinguished between injured athletes who displayed high compared to low levels of rehabilitation adherence following anterior cruciate ligament reconstructive surgery. In order to gain an in-depth and comprehensive understanding of these factors, unstructured qualitative interviews were conducted with six high adherers, six matched low adherers and for each injured athlete, a significant other. Thematic analysis was used to identify the themes that distinguished between high and low adherers. The findings revealed three themes: (1) preparation for post-operative rehabilitation; (2) an active versus passive approach to rehabilitation; and (3) the threat of a poor outcome. Each theme comprised a number of sub-themes that further elucidated the participants’ rehabilitation experiences and adherence behaviors. The findings have important practical implications for medical professionals, sport psychology consultants, and coaches and athletes with a vested interest in expediting recovery following an ACL reconstructive surgery.