To assess the usefulness of circulating microRNAs (miRNAs) as non-invasive molecular biomarkers for early prediction of preeclampsia, a differential miRNA profiling analysis was performed in first-trimester pooled sera from 31 early preeclampsia patients, requiring delivery before 34 weeks of gestation, and 44 uncomplicated pregnancies using microfluidic arrays. Among a total of 754 miRNAs analyzed, the presence of 63 miRNAs (8%) was consistently documented in the sera from preeclampsia and control samples. Nevertheless, only 15 amplified miRNAs (2%) seemed to be differentially, although modestly, represented (fold change range: 0.4-1.4). After stem loop RT-qPCR from individual samples, the statistical analysis confirmed that none of the most consistent and differentially represented miRNAs (3 overrepresented and 4 underrepresented) were differentially abundant in serum from preeclamptic pregnancies compared with serum from normal pregnancies. Therefore, maternal serum miRNA assessment at first-trimester of pregnancy does not appear to have any predictive value for early preeclampsia.