OBJECTIVE: Maternal nutrition during pregnancy is a key factor influencing birth outcome. Dietary diversity is a proxy for multiple macro- and/or micronutrient sufficiency of an individual's diet. This systematic review aimed to summarise the findings on the association between maternal dietary diversity during pregnancy and the risk of low birth weight (LBW) in newborns. DESIGN: This is a systematic review study. SETTING: Google and the PubMed, Scopus and Google Scholar databases were searched to extract original studies on humans published until June 2020, without date restrictions. There was no limitation regarding geographic region or economic condition of countries. Duplicated and irrelevant studies were screened out and data were obtained through critical analysis. PARTICIPANTS: Articles that examined the association between maternal dietary diversity during pregnancy and the risk of LBW in infants were included. RESULTS: Of the ninety-eight studies retrieved, fifteen articles were included in the final review. All included articles represent low- and middle-income countries. Eighty percentage of the studies (n 12) indicated that low maternal dietary diversity during pregnancy is associated with an increased risk of LBW infants. Three studies that included a small number of LBW infants and did not take into account factors which may bias study results failed to show this association. CONCLUSION: The results suggest that low maternal dietary diversity during pregnancy may be associated with the risk of LBW, more specifically in developing countries. Dietary diversity might be a valuable predictor of maternal nutrition during pregnancy and the chance of giving birth to a LBW infant.