Context – The negative effects of socioeconomic, environmental and ethnic inequalities on childhood respiratory diseases are known in the development of persistent asthma and can result in adverse outcomes. However, little is known about the effects of these disparities on pediatric intensive care unit (PICU) outcomes in respiratory diseases. Objective – The purpose of this systematic review is to evaluate the literature on disparities in socioeconomic, environmental and ethnic determinants on PICU outcomes. We hypothesize that these disparities negatively influence the outcomes of children’s respiratory diseases at the PICU. Methods – A literature search (in PubMed, Embase.com and Web of Science Core Collection) was performed up to September 30, 2022. Two authors extracted the data and independently evaluated the risk of bias with appropriate assessment methods. Articles were included if the patients were below 18 years of age (excluding neonatal intensive care unit admissions), they concerned respiratory diseases and incorporated socioeconomic, ethnic or environmental disparities. Results – Of 8746 references reviewed, 15 articles were included; seven articles on the effect of socioeconomic status, five articles on ethnicity, one on the effect of sex and lastly two on environmental factors. All articles but one showed an unfavorable outcome at the PICU. Conclusion – Disparities in socioeconomic (such as a low-income household, public health insurance), ethnic and environmental factors (such as exposure to tobacco smoke and diet) have been assessed as risk factors for the severity of children’s respiratory diseases and can negatively influence the outcomes of these children at the PICU.