It is controversial whether gestational hypertension (GH) and preeclampsia (PE) have the same pathophysiology. Our aim was to clarify whether the serum soluble fms-like tyrosine kinase 1 (sFlt-1)/placental growth factor (PlGF) ratio and levels of soluble endoglin (sEng) are different in women with GH and with PE. In women with GH (15 cases), hypertension preceding PE (h-PE, 10 cases) and PE in which hypertension and proteinuria occurred simultaneously (si-PE, 36 cases), blood samples were collected after disease onset. The levels of log(10)(sFlt-1/PlGF) in women with GH were significantly lower than in women with h-PE and si-PE (1.65±0.39 vs. 2.22±0.35 and 2.15±0.46). The levels of log(10)sEng in women with GH were also significantly lower than in women with h-PE and si-PE (1.51±0.43 vs. 1.87±0.21 and 1.85±0.32). The incidence rates of the sFlt-1/PlGF ratio 95th percentile of the reference value were 73, 100 and 92%, respectively, (P=0.080), and those of sEng 95th percentile were 67, 100 and 89%, respectively, (P=0.053). In conclusion, the levels of sFlt-1/PlGF ratio and sEng in women with GH were lower than in those with h-PE and with si-PE; however, the majority of women with GH showed abnormal increases of both sFlt-1/PlGF ratio and sEng, suggesting that GH may be a subclinical PE in view of serum levels of angiogenesis-related factors.