Background: Pilates exercise is recommended for people with chronic low back pain (CLBP). In the literature, however, Pilates exercise is described and applied differently to treat people with CLBP. These differences in the definition and application of Pilates exercise make it difficult to evaluate its effectiveness. Objective: The aim of this study was to establish consensus regarding the definition and application of Pilates exercise to treat people with CLBP. Methods: A panel of Australian physical therapists who are experienced in treating people with CLBP using Pilates exercise were surveyed using the Delphi technique. Three electronic questionnaires were used to collect the respondents' opinions. Answers to open-ended questions were analyzed thematically, combined with systematic literature review findings, and translated into statements about Pilates exercise for people with CLBP. Participants then rated their level of agreement with these statements using a 6-point Likert scale. Consensus was achieved when 70% of the panel members strongly agreed, agreed, or somewhat agreed (or strongly disagreed, disagreed, or somewhat disagreed) with an item. Results: Thirty physical therapists completed all 3 questionnaires and reached consensus on the majority of items. Participants agreed that Pilates exercise requires body awareness, breathing, movement control, posture, and education. It was recommended that people with CLBP should undertake supervised sessions for 30 to 60 minutes, twice per week, for 3 to 6 months. Participants also suggested that people with CLBP would benefit from individualized assessment and exercise prescription, supervision and functional integration of exercises, and use of specialized equipment. Limitations: Item consensus does not guarantee the accuracy of findings. This survey reflects the opinion of only 30 physical therapists and requires validation in future trials. Conclusion: These findings contribute to a better understanding of Pilates exercise and how it is utilized by physical therapists to treat people with CLBP. This information provides direction for future research into Pilates exercise, but findings need to be interpreted within the context of study limitations.