Background Diagnostic imaging is frequently requested for non-specific low back pain despite limited clinical value. Patient desire for imaging remains a key driver of low-value referrals, yet little is known about the anticipatory biopsychosocial beliefs that shape this preference. The aim of this study was to explore anticipatory patient beliefs and the underlying psychosocial dimensions that contribute to imaging desire in non-specific low back pain.Methods A qualitative study using interpretative phenomenological analysis was conducted with 10 adults experiencing non-specific low back pain in the UK. Semi-structured interviews explored participants' lived experiences to understand anticipatory beliefs about diagnostic imaging desire. Analysis followed an idiographic–cross case approach, supported by reflexive practices and collaborative interpretation.Results Three interlinked themes were identified. Illness identity and credibility captured how imaging was viewed as objective validation of legitimised symptoms, supported social acceptance, and represented “good care”. Managing cognitive threat reflected how imaging was used to address fear of missed pathology, uncertainty and unresolved threat. Healthcare navigation illustrated how imaging was perceived as a guide through care pathways, influencing expectations, relationships, and patients’ sense of control.Conclusions Imaging desire in non-specific low back pain is partially driven by complex anticipatory beliefs centred on legitimacy, threat reduction, and navigation needs. Further understanding the influential biopsychosocial dimensions of imaging desire is critical for supporting tailored dialogue, expectation management, and shared decision-making to reduce low-value imaging.