Abstract Background Identifying patients who will benefit from spine surgery is still a challenge. This is especially the case when patients’ complaints and medical history, together with clinical observations, do not correspond to structural pathological changes. With inpatient gradual diagnostics (IGD)—the administration of analgesic and anti-inflammatory agents to a special area of interest—the effect of surgery can be temporarily simulated. From the patient’s statement about the alleviation of pain, the surgeon can draw conclusions concerning its causes. The aim of this study was to evaluate the extent to which IGD influences the decision about the nature and scope of surgical treatment strategies, and the way in which it does so, in patients with chronic lumbar back pain. Methods Clinical history and radiologic images were analysed retrospectively in 116 patients by two spine surgeons. Two therapeutic recommendations were developed for each patient: one was based on knowledge before IGD and one on knowledge after IGD. Results IGD changed the treatment strategy in 39 % of the analysed cases. Although the rate of recommended surgery was reduced by about 10 %, the indicated surgical scope increased in 25 % of cases. Conclusions IGD is an established concept used to determine therapeutic strategies in patients with chronic lumbar back pain. In our analysed cases, IGD led to highly relevant changes in recommendations for further surgical treatment.