Smoking does not only endangers the smokers themselves but will also harm the people around them. These are the non-smokers also called the passive smokers or second-hand smoke.In particular pregnant women who are the second-hand smoke can lead low birth weight (LBW) babies. This study aims to determine the impact of second- hand smoke in pregnancy toward LBW in the district of Aceh Besar in 2016. A case control study was done in district of Aceh Besar, Aceh province, Indonesia. The total sample was 120 neonates (1:1), 60 neonates were LBW (cases) and 60 neonates were normal weight (controls). Data collection was doneusing a questionnaire filled in by the parents. The univariate analysiswas described with percentages and the Wald-Wolfowithz run test was used for the bivariate analysis. The results showed that the majority of mothers had a good knowledge about the dangers of smoking, ie 91 or 75.8%. Most of the mothers had positive attitudes for male smokers. The smoking men are considered normal and acceptable, consisting of 73 mothers or 60.8%. All the mothers in this study were non-smokers (100.0%). The majority of the fathers were smokers, 88 or 73.3%, and most of them smoked around their pregnant wife, 55 fathers or 62.5%. The results of the bivariate analysis indicated there was a significant impact of the second-hand smoke toward the LBW (P value <0.05). It means, mothers as a second-hand smoke during pregnancy have a risk to born the LBW baby
second-hand smoke ; pregnancy ; low birth weight (LBW)