Background: Preeclampsia (PE) may represent an inflammatory process. Endocan (ESM-1) is a marker of endothelial inflammation. We compared plasma endocan levels between PE and control groups and between early and late-onset PE. Study design: Maternal plasma endocan levels were measured in 41 preeclampsia (PE) pregnancies - 25 early-onset (<34 weeks); 16 late-onset (>= 34 weeks), and 37 non-complicated pregnancies (22 matched with early-onset PE, 15 with late onset). Results: There was no significant differences between plasma endocan levels of patients with PE and control group (468.8(IQR: 169.7)ng/L vs 462.4(IQR: 321.1)ng/L, p > 0.05), between early and late-onset PE (458.8(221.8)ng/L vs 469.8(122.6)ng/L, p > 0.05), between early-onset PE and corresponding control group (458.8(221.8)ng/L vs 506.2(1481.9)ng/L, p > 0.05), or late-onset PE and corresponding control group (469.8(122.6)ng/L vs 451.0(85.1)ng/L, p > 0.05). Conclusion: There was no significant difference between endocan levels of early or late-onset PE compared with their corresponding control groups, nor between early and late-onset preeclampsia groups.