Objective: To explore which factors led to drop-out in patients of Turkish and Moroccan origin with chronic nonspecific low back pain who participated in a rehabilitation programme. Subjects: Patients of Turkish or Moroccan origin with chronic non-specific low back pain (n=23) from 2 rehabilitation centres and 4 rehabilitation departments of general hospitals in the Netherlands. Methods: In-depth semi-structured interviews were conducted with patients of Turkish and Moroccan origin (n=23), rehabilitation physicians (n=8) and rehabilitation therapists (w=2). Interviews were transcribed or summarized and subsequently coded and analysed according to themes. Results: Most patients dropped out due to expectations of a specific medical diagnosis and pain relief as the main aims of rehabilitation treatment. Other reasons for drop-out detected in the interviews were: lack of acknowledgement of the patient's complaints, lack of trust in the rehabilitation physician, contradicting views to those of the physician from the patients' country of origin with regard to the cause and treatment of pain, and communication problems. Conclusion: The major reason for drop-out was patients having different expectations, from those of their health providers, of the aim of treatment, as a result of a different view of the origin and treatment of low back pain. © 2010 Foundation of Rehabilitation Information.