Objective: To investigate Helicobacter pylori seropositivity rate in preeclamptic and healthy pregnants. Additionally, we compared serum malondialdehyde (MDA) levels and lipid profile between H. pylori-positive and negative cases. Method: This study included 53 preeclamptic and 30 healthy pregnants. Serum levels of total cholesterol (TC), triglyceride (TG), high-density lipoprotein (HDL-C) and low-density lipoprotein (LDL-C), MDA, and H. pylori Ig G antibodies were measured. Results: Preeclampsia group had higher serum MDA levels compared with healthy pregnants (P<0.001). While the rate of H. pylori seropositivity was 43/53 (81%) in the preeclampsia group, this was 18/30 (% 60) in normal pregnants (odds ratio (OR), 2.86; 95% confidence interval (CI), 1.05-7.82; P=0.036). We further divided the preeclampsia group as H. pylori-positive and H. pylori-negative subgroups. In H. pylori-positive group, serum TC (P<0.01) and LDL-C (P<0.01) levels were significantly higher than those of H. pylori-negative group. Mean MDA concentration was higher in H. pylori-positive group than that of H. pylori-negative group (P<0.001). Conclusion: H. pylori-positive pregnants may have a high risk for preeclampsia and H. pylori may be one of the causes for high MDA levels in preeclampsia.