Aim: The aim of the study was to retrospectively assess diagnostic difficulties in paraspinal bone cancers as noted in the authors’ centre in 2009–2016. Material and methods: The study was performed in a group of 7 patients aged 3.5–17 years with paraspinal tumours, which constitutes 16.6% (7/42) of all children with bone cancers treated in the authors’ centre. The analysis involved: reported symptoms, time from the onset of the first symptoms to the correct diagnosis, type and stage of cancer, and treatment outcomes. Results: The most common symptom was pain in the lumbosacral region. In all cases, the first symptoms were considered to be the consequences of musculoskeletal system dysfunction. They persisted for 12–28 weeks before cancer was diagnosed. In this period, none of the children had spine radiography or any other diagnostic tests performed. The final diagnosis was determined on the basis of a histopathological examination. The most common were malignant tumours with extensive neoplastic infiltration. Two patients underwent radical surgery, and the remaining children required additional intensive chemotherapy. Moreover, proton therapy was implemented in 1 case. One patient died due to tumour progression, a patient with chondroblastoma is still being treated, and the remaining patients are in remission, but, due to tumour location, the prognosis is uncertain. Conclusions: 1) Cancer must be considered in children with recurrent back pain. 2) Plain radiography should be the basic diagnostic test. 3) Persisting back pain with normal radiography is an indication for magnetic resonance imaging or computed tomography, or for extending the range of imaging. 4) Imaging should be performed prior to rehabilitation for back pain.