ObjectiveTo evaluate the use of social media (SM) as a source of health information among patients with chronic low back pain (LBP) and to evaluate the factors associated with this use.MethodsThis was a cross‐sectional study involving patients with chronic LBP. Information on their sociodemographics, LBP characteristics, and comorbidities was collected. With the use of a questionnaire, we evaluated the use of SM as a source of information, examining the frequency of use, the type of SM used, and degree of confidence and application of information found. Catastrophising, trust in physicians, and concerns regarding medicines were assessed through the Pain Catastrophizing Scale (PCS), Trust in Physician Scale (TPS) and Beliefs about Medicines Questionnaire (BMQ Specific Concerns). A regression analysis was conducted to identify factors associated with the use of SM.ResultsA total of 118 patients were included. The mean age was 53.01 ± 14.09 years. Of the sample, 68.6% sought information regarding their LBP on social networks. The main source was YouTube (30%). Eighteen point six percent of patients trusted the information found through SM, and 16.1% have already acted on some of this information. The majority of patients (82%) would prefer to have healthcare professionals in their virtual spaces to answer their questions. In a multivariate analysis, only the degree of trust in the physician was negatively associated with SM use (OR = 0.95 IC 95% [0.91–0.99]; p = 0.03).ConclusionThis survey showed that a proportion of patients suffering from chronic LBP use SM, YouTube in particular, as a source of health information. The level of trust in physicians was the strongest factor that impelled people to use SM as a source of health information.