Diverse views exist regarding the underlying nature of nonspecific low bak pain (NSLBP). This study aimed to (i) develop a conceptual framework of NSLBP based on the expressed beliefs of those who treat and/or research NSLBP and (ii) determine whether these beliefs are discretely clustered and whether they are associated with participant characteristics. Surveys were completed by participants (n = 62) of the 2006 Amsterdam International Low Back Pain Forum and a low back pain meeting (n = 488) in Melbourne. Respondents reported beliefs regarding the nature of NSLBP, Probabilistic data-mining was used to detect clusters of belief and between group differences were tested using Mann-Whitney U tests. Overall, there was an 84 response rate. Diverse beliefs were reported but multiple clusters of belief to explain this diversity were not apparent. Whether predominantly engaged in clinical or research activity, people expressed similar beliefs, except that clinicians placed greater value on measures of physical impairment. There were conflicting views within the clinical and research community regarding the underlying nature of NSLBP. Within the constructs sampled, no unifying framework could explain the diversity of current beliefs. This is likely to reflect pervasive uncertainty about the etiology, and therefore best practice assessment, of NSLBP.