BACKGROUND The association between excessive gestational weight gain (GWG) and the risk of hypertensive disorders of pregnancy (HDP) remains uncertain in women with increased water retention in late gestation associated with the pathophysiology of HDP. This study aimed to investigate the association between GWG before the third trimester and the risk of HDP. MATERIAL AND METHODS This was a prospective cohort study in singleton-pregnant women in Tianjin, China, from 2016. Generalized linear models were used to analyze the relationship between weight gain and the risk of HDP. RESULTS A total of 5295 singleton-pregnant women were included. Even after adjusting for relevant confounders, weight gain at approximately 28 weeks remained an independent risk factor for HDP in the normal-weight group. Compared to the reference of low weight gain (+1 SD was associated with an approximately 2.0 times greater likelihood of HDP (RR: 2.08, 95% CI: 1.06-4.08). Moreover, there was a positive relationship between weight gain in the short interval of early pregnancy and risk of HDP in overweight women. CONCLUSIONS Excessive weight gain before the third trimester was associated with a greater risk of developing HDP among women with early-pregnancy normal weight, which may provide a chance to identify subsequent hypertensive disorders. Additional research is needed to determine whether early-pregnancy weight gain is associated with HDP risk.