Low birth weight (<2500 g) is an important public health indicator of both maternal and child health. It increases the risk of neonatal mortality and morbidity, growth inhibition, impaired cognitive development and chronic diseases later in life. Low birth weight is more prevalent in developing countries, where smokeless tobacco use is also common and socially and culturally accepted, as compared to smoking among women. Smokeless tobacco refers to tobacco products such as khat, betel, khaini, gutka, snuff and areca nut; which are consumed by means other than smoking/burning, and can be used nasally or orally. This study systematically reviews evidence on the adverse association between maternal smokeless tobacco use and low birth weight. A systematic search of studies was conducted using electronic databases (PubMed, CINAHL, EMBASE, Scopus), along with reference list searching, with no limitation on language and date of publication. Article selection and data extraction were performed by two independent reviewers. A comprehensive quality assessment of all included studies was performed using the Newcastle Ottawa Scale. Significant associations with smokeless tobacco use were seen in 11 out of the 29 included studies for LBW. However, these results may be limited by confounding and bias. There is also a limited number of studies which evaluate the presence of a dose response relationship between smokeless tobacco use and birthweight. Further research and quality observational studies are needed to strengthen this evidence base. The adverse effects of smokeless tobacco found in this review highlights the need for policies which focus on primary prevention of smokeless tobacco use. Pregnant women should be provided with intensive education, counselling and resources regarding quitting or cutting down smokeless tobacco use to improve both maternal and child health outcomes. However, this is a challenging matter due to the addictive nature of tobacco.