Providing information to patients regarding appropriate management of LBP is a crucial component of primary care and treatment of low back pain (LBP). Limited knowledge is available, however, about the information delivered by physicians to patients with low back pain. Hence, this study aimed at evaluating (1) the self-reported practices of French physicians concerning information about patients with acute LBP (2) the consistency of these practices with the COST B13 guidelines, and (3) the effects of the delivery of a leaflet summarizing the COST B13 recommendations on the management of patient information, using the following study design: 528 French physicians [319 general practitioners (GP) and 209 rheumatologists (RH)] were asked to provide demographic information, responses to a Fear Avoidance Beliefs questionnaire adapted for physicians and responses to a questionnaire investigating the consistency of their practice with the COST B13 guidelines. Half of the participants (163 GP and 105 RH) were randomized to receive a summary of the COST B13 guidelines concerning information delivery to patient with low back pain and half (156 GP and 104 RH) were not given this information. The mean age of physicians was 52.1±7.6 years, 25.2% were females, 75% work in private practice, 63.1% reported to treat 10-50 patients with LBP per month and 18.2%<10 per month. The majority of the physicians (71.0%) reported personal LBP episode (7.1% with a duration superior to 3 months). Among the 18.4% (97) of the physicians that knew the COST B13 guidelines, 85.6% (83/97) reported that they totally or partially applied these recommendations in their practice. The average work (0-24) and physical activity (0-24) FABQ scores were 21.2±8.4 and 10.1±6.0, respectively. The consistency scores (11 questions scored 0 to 6, total score was standardized from 0 to 100) were significantly higher in the RH group (75.6±11.6) than in GP group (67.2±12.6; p<0.001). The delivery of a summary of the COST B13 guidelines significantly improved the consistency score (p=0.018). However, a multivariate analysis indicated that only GP consistency was improved by recommendations' delivery.The results indicated that GP were less consistent with the European COST B13 guidelines on the information of patients with acute LBP than RH. Interestingly, delivery of a summary of these guidelines to GP improved their consistency score, but not that of the RH. This suggests that GP information campaign can modify the message that they deliver to LBP, and subsequently could change patient's beliefs on LBP.