Background: Anxiety and depression are known comorbidities of chronic back pain. Their psychological predictors are not well established in patients with chronic back pain qualified for neurosurgery. Aims: The purpose of this study was to determine the psychological predictors of depression and anxiety in patients with chronic back pain qualified for surgery. Design: This was a cross-sectional study. Settings: A neurosurgical ward in Gdańsk, Poland. Participants/Subjects: All patients who were admitted to the neurosurgical ward and met the inclusion criteria were recruited for the study. Finally, 83 patients with chronic back pain waiting for surgery were recruited. Methods: A battery of questionnaires, including Illness Perceptions Questionnaire–Revised, Multidimensional Health Locus of Control Scale, Hospital Anxiety and Depression Scale, and Brief Pain Inventory, was used in 83 spinal surgery candidates. Results: Higher anxiety was predicted by stronger beliefs about negative consequences of illness (β = .205, p < .05), worse illness coherence (β = .204, p < .05), negative emotional representations of illness (β = .216, p < .05), and depression (β = .686, p < .001). Higher depression was predicted by anxiety (β = .601, p < .001), pain interference (β = .323, p < .01), lower personal control over pain (β = −.160, p < .05), and lower external control of health (β = −.161, p < .05) but, surprisingly, higher internal control of health (β = .208, p < .01). Conclusions: Anxiety and depression commonly coexist in chronic back pain sufferers qualified for spine surgery but are derived from dissimilar beliefs. The results highlight the usefulness of advising about the disease and treatment in comprehensive care for this group of patients.