Purpose <p>The aim of this study was to compare the incidence of pneumonia and pneumonia-related mortality in children with cerebral palsy (CP) and scoliosis, with and without scoliosis surgery.</p> Methods <p>National registries were searched for individuals with CP and scoliosis born after 1987 with recordings between 1996 and 2021. Identified individuals were categorized according to scoliosis surgery and were compared for pneumonia incidence and pneumonia-related mortality. Multivariable Cox regression examined determinants of mortality.</p> Results <p>We identified 474 children with CP and scoliosis, of these 236 children had not undergone surgery, while 238 had been operated. Both groups had similar rates of comorbidities. While there was no change in number of individuals with at least one hospitalization for pneumonia, there was significant reduction in cumulative pneumonia incidence from before to after surgery (175.5 vs. 121.5 hospitalizations per 1,000 years, <i>p</i> &lt; 0.001), while incidence did not change in non-surgically treated patients (192.8 vs. 203.9, hospitalizations per 1,000 years, <i>p</i> = 0.35). During follow-up pneumonia-related mortality was significantly higher in the non-surgically treated group than in the surgically treated group (<i>n</i> = 21/236, 8.9% vs. <i>n</i> = 8/238, 3.3%, <i>p</i> = 0.008). After adjusting for covariates surgical patients had 87.5% reduction in risk of mortality to pneumonia compared with non-surgically treated patients (hazard ratio: 0.125, 95% confidence interval: 0.051–0.31, <i>p</i> &lt; 0.001).</p> Conclusions <p>These results indicate that surgical treatment of scoliosis in children with CP associates to reduced incidence of pneumonia and pneumonia-related mortality.</p>