OBJECTIVE: Information regarding the association of immune-related factors with pneumonia in children with coronavirus disease 2019 (COVID-19) is scarce. This study aims to summarize the immune-related factors and their association with pneumonia in children with COVID-19. METHODS: Children with COVID-19 at Wuhan Children's Hospital from 28 January to 12 March 2020 were enrolled. Pneumonia due to causes other than COVID-19 were excluded. The clinical and laboratory information including routine blood tests, blood biochemistry, lymphocyte subsets, immunoglobulins, cytokines, and inflammatory factors were analyzed retrospectively in 127 patients. Normal ranges and mean values of laboratory markers were applied as parameters for logistic regression analyses of their association with pneumonia. RESULTS: In nonintensive care unit patients, 48.8% and 22.4% of patients had increased levels of procalcitonin and hypersensitive C-reactive protein (hs-CRP) respectively. A total 12.6% and 18.1% of patients had decreased levels of immunoglobulin A (IgA) and interleukin 10 (IL-10), respectively. Approximately 65.8% of patients had pneumonia. These patients had decreased levels of globulin (odds ratio [OR], 3.13; 95% confidence interval [CI] 1.41-6.93; P = .005), IgA (OR, 4.00; 95% CI, 1.13-14.18; P = .032), and increased levels of hs-CRP (OR, 3.14; 95% CI, 1.34-7.36; P = .008), procalcitonin (OR, 3.83; 95% CI, 2.03-7.24; P < .001), IL-10 (OR, 7.0; 95% CI, 1.59-30.80; P = .010), and CD4(+) CD25(+) T lymphocyte less than 5.0% (OR, 1.93; 95% CI, 1.04-3.61; P = 0.038). CONCLUSION: Decreased IgA and CD4(+) CD25(+) T lymphocyte percentage, and increased hs-CRP, procalcitonin, and IL-10 were associated with pneumonia, suggesting that the immune-related factors may participate in the pathogenesis of pneumonia in children with COVID-19.