Objectives: Intrauterine growth restriction (IUGR) is diagnosed when the estimated fetal weight remains below the 10th percentile of gestational age based on pathological restriction of growth and/or accompanying Doppler abnormalities. Endothelial dysfunction is a common pathogenetic pathway underlying IUGR etiology. Endocan (ESM-1) is a novel marker of endothelial dysfunction and inflammation found in the maternal circulation. This study was designed to compare plasma endocan levels between pregnancies complicated with IUGR and a control group. Study design: Forty-four pregnancies complicated with IUGR and 47 healthy pregnancies were included. Maternal plasma endocan levels were detected by ELISA. Parametric data was studied by Student's t-test. Mann-Whitney U-test was used in analyzing non-parametric data. Categorical variables underwent chi-square test. ROC analysis was performed to define the cutoff value of endocan in detecting IUGR. Spearman correlation test was performed. Results: Maternal plasma endocan level varied significantly between IUGR and healthy pregnancies and was 1.8 fold higher in the IUGR group (793.0 (IQR:544.4-1896.0) ng/L vs. 441.8 (IQR: 408.3-512.4) ng/L, p < .001). There was a weak negative correlation between endocan level and 5th and 10th minute APGAR Scores (r = -0.256; p = .015 and r = -0.215; p = .042, respectively), a weak positive correlation with umbilical artery pulsatility index, and a moderate negative correlation with cerebroplacental ratio (r = 0.394; p < .001 and r = -0.459; p < .001, respectively). Conclusions: There was a significant difference between endocan levels of IUGR and healthy pregnancies. Further studies might be designed to investigate the performance of endocan in predicting neonatal outcomes for pregnancies complicated with IUGR.