Purpose: Physiotherapists are key providers of care for patients with low back pain (LBP); however, information on Canadian physiotherapists’ use of evidence-based clinical practice guidelines (EBCPGs) for LBP is lacking. We aimed to (1) describe Canadian physiotherapists’ adherence to EBCPGs for LBP; (2) compare beliefs and attitudes of physiotherapists with higher and lower adherence; (3) identify predictors of adherence; and (4) gather physiotherapists’ perceptions about the care provided to patients with LBP. Method: This mixed methods study involved two phases: (1) a survey containing a LBP clinical scenario and (2) qualitative semi-structured interviews with physiotherapists. Results: A total of 406 (77%) of the 525 survey respondents demonstrated higher adherence (score of 3 or 4) to EBCPGs; however, only 29.5% chose interventions to address psychosocial issues. Postgraduate training was the strongest predictor of higher adherence. Interviewed physiotherapists reported being highly satisfied with the care provided to patients with LBP even when psychosocial issues are present, despite low confidence in addressing those issues. Conclusions:Although overall adherence was high, Canadian physiotherapists do not frequently address psychosocial issues with LBP patients, and often do not feel confident or competent in that aspect of practice. This suggests an opportunity for developing additional training for addressing psychosocial issues in LBP patients.