Background <p>Achondroplasia (ACH) is the most common skeletal dysplasia characterized by disproportionate short stature due to impaired endochondral ossification. One of the most critical and potentially fatal complications of ACH is foramen magnum and upper cervical canal stenosis. Compression at the cervicomedullary junction may lead to myelopathy, hypotonia, developmental delay, and central sleep apnea. Early detection and timely surgical intervention are essential to prevent permanent neurological injury.</p> Methods <p>This retrospective study evaluated 15 pediatric patients with ACH (9 girls, 6 boys; age range 3–42 months, mean 17.2 months) who underwent foramen magnum decompression and C1 laminectomy at Marmara University Neurosurgery Department between 2016 and 2025. All patients underwent comprehensive neurological and radiological evaluation, including MRI and 3D CT of the craniovertebral junction, and were classified by the Achondroplasia Foramen Magnum Score (AFMS).</p> Results <p>Nine patients had AFMS level 4 stenosis and six had level 3. The anteroposterior diameter of the foramen magnum ranged from 4.03 to 11.03 mm, with an area between 17.40 and 105.16 mm². Presenting symptoms included motor delay (<i>n</i> = 4), respiratory disturbances or central apnea (<i>n</i> = 4), and macrocephaly (<i>n</i> = 3). Postoperative imaging confirmed adequate decompression in all patients. Neurological and respiratory improvement occurred in all patients except one with persistent hypotonia. One patient died early postoperatively due to recurrent pneumonia and sepsis. Complications were minimal.</p> Conclusion <p>Foramen magnum decompression with C1 laminectomy is a safe and effective procedure for infants and children with achondroplasia presenting with cervicomedullary compression. Early radiological and neurological evaluation, particularly with AFMS, facilitates accurate surgical decision-making and improves outcomes.</p>