Background: Craniovertebral junction (CVJ) instrumentation and fusion in childhood are frequently performed with either sublaminar wires or screws in lateral masses, and both are considered quite safe procedures. Methods: Our experience deals with 12 children: six (mean age 9.5 years) harbouring a congenital instability associated with Down’s or Morquio’s syndromes and primary os odontoideum; and six (mean age 11.5 years) with acquired iatrogenic instability due to transoral anterior decompression for different reasons (inferior clivectomy, anterior arch removal and odontoidectomy). All patients in the ‘congenital group’, except for one, had preoperative dynamic x-rays and underwent surgical correction by means of posterior wiring, fusion and an external orthosis. All patients in the ‘iatrogenic group’ had no preoperative dynamic x-rays and underwent a screwing technique with fusion and an external orthosis. Results: The postoperative clinical picture had improved in all patients at the latest follow-up (observation range 63–202 months [mean 118.5 months]), with neuroradiological confirmation of satisfactory bony fusion and with neural decompression in all patients. Conclusion: Although it requires a more accurate preoperative neuroradiological setting, the screwing technique takes less time and is characterized by less blood loss and less postoperative discomfort than the wiring technique. The latter features confirm the simplicity, safety (continuous fluoroscopic assistance is not necessary, and there is no risk of neurovascular injuries) and lower expense (neither complex hardware devices nor neuronavigation systems are required) of the screwing technique.