Background: Pneumonia is an inflammation of the lung parenchyma caused by pathogenic microorganisms such as bacteria, viruses, fungi, and parasites that can occur together with lower respiratory tract infections. Pneumonia is the cause of death for more than 800,000 children under five worldwide in 2017. One of the risk factors for pneumonia is a history of breastfeeding (ASI). This study aimed to estimate the effect of non-exclusive breastfeeding on the risk of pneumonia in children under five.Subjects and Method: This meta-analysis was conducted by systematically reviewing similar primary articles from PubMed, Google Scholar, and Springer Link. The articles that were analyzed by the meta-analysis were articles published from 2011 to 2019. PICO compiled the problem formulation: Population: children under five, Intervention: non-exclusive breastfeeding, Comparison: exclusive breastfeeding, Outcome: pneumonia. Keywords for searching articles: "exclusive breastfeeding" OR "breast milk" AND "pneumonia," "exclusive breastfeeding" AND "pneumonia children under five" AND "multivariate" AND "case control." The inclusion criteria used were full paper, used English and Indonesian, and the case-control study design. The results were reported with adjusted odds ratio. Articles were collected using PRISMA diagrams and analyzed using Review Manager 5.3.Results: A total of 9 primary articles were analyzed using meta-analysis with a total sample size of 2,837 children under five. The meta-analysis of case-control studies showed that non-exclusive breastfeeding increased the risk of pneumonia in children under five (aOR= 4.00; 95% CI= 2.75 to 5.81).Conclusion: Non-exclusive breastfeeding increases the risk of pneumonia in children under five.Keywords: non-exclusive breastfeeding, pneumonia, meta-analysisCorrespondence: Putu Anggi Widia Karmany. Masters Program in Public Health. Universitas Sebelas Maret, Jl. Ir. Sutami 36A, Surakarta 57126, Central Java. Email: putuanggiwidiakarmany@gmail.com.Journal of Epidemiology and Public Health (2020), 05(04): 393-401https://doi.org/10.26911/jepublichealth.2020.05.04.01