OBJECTIVES: To determine participant experience of exercise programs for nonspecific chronic low back pain (NSCLBP). Systematic reviews have concluded that exercise is effective for decreasing pain and improving function in adults with NSCLBP. Participation is a key ingredient in exercise and patient's experiences during these programs may be important in influencing outcomes. DESIGN: Qualitative methods with three focus groups facilitated by an independent, experienced facilitator. METHODS: Eighteen people aged over 18 years were included. They had to speak, read and understand English and participated in an exercise program for NSCLBP. Each group was guided with a series of predetermined questions to elicit their experience of participation in exercise programs. Participants were encouraged to give personal opinions freely. Transcribed data were read independently by two researchers and analysed thematically with grounded theory. RESULTS: Stigma emerged as a significant theme in all focus group transcripts. The results demonstrate that people with NSCLBP experience both subtle and overt stigmatization. The following subthemes emerged: stigma perpetrated by health care providers; stigma facilitated by the "sickness versus wellness" model; stigma applied by friends, family, the community, the workplace, and the low back pain subgroup; stigma-associated diagnostic uncertainty and the need for pathology driven validation. CONCLUSIONS: The ramifications of stigma and discrimination are enduring, potentially disabling and appear to interfere with care-seeking, rehabilitation participation, and potentially, rehabilitation outcomes. Public and health professional education, low back pain-specific support groups and dissemination of success stories may help to alleviate stigma.