Background/Objectives: Physiotherapists face significant challenges in managing chronic pain; a complex condition best addressed through a biopsychosocial (BPS) approach. Although substantial evidence exists globally, research specific to Spain remains limited. This study explores the experiences and challenges Spanish physiotherapists encounter in integrating BPS elements across public and private healthcare settings. Methods: Semi-structured interviews with 12 experienced physiotherapists were conducted, using a qualitative approach with purposive sampling and reflexive thematic analysis. The analysis, grounded in a constructivist/interpretivist framework, allowed themes to emerge naturally from the data, supported by relevant quotes. Results: Three primary themes were identified: (1) challenges in implementing the BPS approach, including patient resistance and limited training; (2) facilitators for adopting the BPS model, such as multidisciplinary support and positive patient outcomes; and (3) emotional and psychological aspects of the physiotherapists. The findings highlight the complexities of chronic pain management in physiotherapy, emphasizing the need for enhanced psychological training, integrated multidisciplinary care, early diagnosis, and effective family involvement. These insights are critical for improving both patient care and physiotherapist well-being. Conclusions: This study provides valuable guidance for future strategies, focusing on educational enhancements, multidisciplinary collaboration, healthcare policy reform, and emotional support for physiotherapists within the Spanish healthcare context.