OBJECTIVE The aim of this study is to examine the relationship between placental localisation, birth weight, and foetal sex. It also evaluates umbilical artery Doppler parameters and their relationship with placental localisation. METHODS This is a retrospective study of 500 healthy pregnant women who gave birth at our university. All women had undergone a detailed ultrasound and Doppler examination at 20-23 weeks. The ultrasonography results of the patients were examined retrospectively. Foetal biometry, birth weight, and umbilical artery Doppler parameters were recorded and compared according to placental localisation. RESULTS Birth weight was significantly higher in foetuses with anteriorly located placenta. The incidence of female foetuses was higher (62%) in relation to anteriorly located placentas, whereas male incidence was higher (51.9%) in relation to posterior placentas. A comparison of Doppler parameters betiveen groups revealed significantly higher pulsatility index (PI) and resistance index (RI) values in posteriorly located placentas. CONCLUSIONS Foetal sex might affect placental localisation. Doppler parameters and birth weight might also differ according to placental side. These factors should be taken into consideration during the evaluation of obstetric patients.