Maternal nutrition is crucial for promoting fetal development and both excessive and inadequate amounts can undermine the offspring’s health, increasing the risk of chronic diseases such as obesity, later in life. Polyunsaturated fatty acids particularly linoleic acid (LA) and alpha-linolenic acid (ALA) play a key role in this process, yet limited information exists on their effects on neonatal anthropometric measures within Australian populations. Aim: This study investigates the association between maternal dietary intake of LA and ALA and neonatal birth outcomes such as birth weight (BW), birth length (BL), and head circumference (HC) in pregnant women living in Melbourne’s western suburbs. Methods: Using an observational study design, following informed consent 198 pregnant women participated in this study. Maternal dietary intake was assessed during the second (FD1) and third (FD2) trimesters through 3 days food diaries and a food frequency questionnaire (FFQ) designed to capture habitual dietary intake. Neonatal birth dimensions were recorded and correlated with dietary LA and ALA intake. Results: Significant difference in ALA intake across birth weight groups were observed using FD1 only. The study identified significant associations between maternal dietary LA and ALA intake during second trimester (FD1) and neonate’s BL (p < 0.05). Conclusion: This study highlights how different dietary assessment methods and timing of assessment can impact the outcomes observed. The findings further provide evidence suggesting a potential association between maternal dietary intake of LA and ALA intake during mid – pregnancy and neonatal birth outcomes. Furthermore, ongoing plasma fatty acids assessments may provide additional insights into the effects of maternal diet on neonatal health.