Phototherapy is the mainstay of treatment of neonatal hyperbilirubinaemia. Periodic change in position of the neonate under phototherapy (from supine to prone or lateral positions) may improve the efficiency of phototherapy by hastening the access of phototherapy light to bilirubin deposited in different parts of the skin and subcutaneous tissue. To evaluate the effects of periodic change of body position during phototherapy as compared to no prescribed change in body position, on serum total bilirubin level and duration of treatment in neonates with unconjugated hyperbilirubinaemia during the first 28 days of life. Secondary objectives of the review included evaluation of the efficacy of periodic change of body position on the need for or number of exchange transfusions, incidence of bilirubin-induced neurological damage (BIND), side effects of phototherapy, and sudden infant death syndrome (SIDS). We used the standard search strategy of Cochrane Neonatal to run comprehensive searches in the Cochrane Central Register of Controlled Trials (CENTRAL; 2021, Issue 3) in the Cochrane Library and Ovid MEDLINE and Epub Ahead of Print, In-Process & Other Non-Indexed Citations, Daily and Versions on 5 March 2021. We also searched clinical trials databases and the reference lists of included studies and relevant reviews for randomised controlled trials (RCTs) and quasi-RCTs. We included RCTs and quasi-RCTs if they enrolled neonates (term and preterm) of either gender with unconjugated hyperbilirubinaemia requiring phototherapy and compared periodic change of the body position of the infant under phototherapy with no prescribed change in body position. Two review authors independently assessed trial quality and extracted data, consulting with a third review author in the case of disagreement. We used standard Cochrane methodological procedures, including assessing the risk of bias of included studies. We used the GRADE approach to assess the certainty of evidence. Primary outcomes were the duration of phototherapy and rate of fall of serum bilirubin at 24 hours. Secondary outcomes included the need for exchange transfusion, number of exchange transfusions, incidence of BIND, and SIDS. We included five studies (343 neonates) with an overall high risk of bias in the review. The body position under phototherapy was changed every two hours or every two-and-a-half hours in two studies each, and every three hours in one study. Three of the five studiesincluded healthy term neonates, whilst the other two studies also included preterm neonates (â„ 33 weeks' gestation); however, separate data about review outcomes in preterm neonates were not available. Periodic change in body position may lead tolittle or no difference in the duration of phototherapy (mean difference (MD) 1.71 hours, 95% confidence interval (CI) -3.17 to 6.59 hours; IÂČ = 58%; 4 studies, 231 participants; low certainty evidence). Only one study reported the rate of fall of serum total bilirubin at 24 hours of starting the phototherapy. Periodic change in body position may lead tolittle or no difference in the rateof fall of serum total bilirubin at 24 hours(MD0.02 mg/dL/h, 95% CI -0.02 to 0.06 mg/dL/h; 1 study, 100 participants; low certainty evidence). We downgraded the certainty of evidence to low due to risk of bias and imprecision. None of the included studies reported the need for or number of exchange transfusions, incidence of BIND, or SIDS. Lack of separate data precluded subgroup analysis. The available evidence is insufficient to determine the effects of periodic change of body position compared with no prescribed change of body position under phototherapy. There is low certainty evidence that there may be little or no difference in the duration of phototherapy andrate of fall in bilirubin at 24 hours of starting phototherapy between periodic change in body position and no prescribed change of body position under phototherapy in term and preterm neonates. None of the included studies reported the effect of change of position on the need for or number of exchange transfusions, incidence of BIND, or SIDS. One study is awaitingclassification and could not be included in the review. Further studies are needed to evaluate theeffectof periodic change in body position under phototherapy, especially in neonates with haemolytic hyperbilirubinaemia and in very preterm neonates. The results of this systematic review apply mainly to neonates born at late-preterm or term gestation receiving phototherapy for non-haemolytic hyperbilirubinaemia.