ABSTRACT Objective: Spastic cerebral palsy (sCP) is a cause of early onset scoliosis, although there are no data on its prevalence. Our objective was to determine the prevalence of early onset neuromuscular spinal deformities (SD) in severely compromised children with sCP. Methods: Cross-sectional quantitative, observational, exploratory, and descriptive study. Review of clinical records. Inclusion criteria: age 2 to 5 years, sCP, level V of the GMFCS, residents in our province. X-ray blind reading by 2 observers. The Student t test was used for parametric data and the chi-square test for non-parametric data. Level of statistical significance: p < 0.05. Results: Thirty-eight cases of 158 registered were included. Average age: 3 years 7 months (2 years – 5 years 2 months). Sex: 21 male/17 female. The predominant etiologies were perinatal: 21 (55.3%), and the prevalent nutritional status was eutrophic: 28 cases (73.7%). SD was very frequent: 32 patients (84.2%) without statistical differences between sexes; there were 20 kyphoscoliosis, 1 lordoscoliosis, 6 scoliosis, 5 hyperkyphosis. Mean angular values: 23.9° (10°- 50°) for the frontal plane deformities and 58° (9°- 92º) for the sagittal deformities. Seventeen patients (44.7%) had average pelvic obliquity of 15° (2°- 30°) without differences in patients with and without SD. There was no association between SD and etiology, digestive disorders, seizures, nutritional status, hip excentration, or limb deformities. Conclusions: The prevalence of SD in children up to 5 years old with severe sCP is high: 84.2% (32/38 cases). The orthopedic profile is children with sCP of any etiology at GMFCS level V, with multiple disabilities and independently of associated limb deformities. Level of evidence I; Diagnostic Studies - Investigating a Diagnostic Test: Testing of previously developed diagnostic criteria on consecutive patients (with universally applied reference “gold” standard).