Assessment and treatment responses were compared in 17 subjects with chronic low back pain assessed as showing at least one clear consciously produced inconsistency in statements and/or behaviors during their participation in an interdisciplinary treatment program and 143 subjects assessed as showing no such inconsistency. Numerous statistically significant differences emerged: Inconsistent subjects were more likely to have pending litigation and to be assessed by staff as showing a higher degree of focus on pain and more dramatized complaints, lower levels of medical findings and attention and interest in treatment, and poor compliance with treatment and assessment procedures. In addition, these subjects reported lower levels of physical activity and generally more inconsistent or negative responses to lumbar sympathetic injections with fewer expected changes in physical sensations. Though not definitive, these results suggested a syndrome of characteristics among such subjects which are similar to those proposed as likely characterizing malingerers. The need for a particularly careful validation of self-report data in patients showing many of these characteristics was emphasized.