This retrospective study assessed fasting plasma glucose (FPG) and body mass index (BMI) during the first trimester of pregnancy as potential screening indicators of later gestational diabetes mellitus (GDM). The study population included 820 pregnant women who delivered in our hospital between 17 September 2013 and 3 March 2014. Demographics and baseline characteristics were collected at the first antenatal visit; FPG levels were measured at 8 or 9 weeks. All participants underwent a 75-g oral glucose tolerance test at 24-28 weeks gestation. Multivariate logistic regression and receiver operating characteristic curve analysis were performed to determine the diagnostic power of risk factors. GDM was diagnosed in 20.3% of the women. There was an increased prevalence of GDM with advancing age, parity, high FPG, and obesity, but not in women with family predisposition. FPG (OR: 3.984; 95% CI: 2.397-6.62) and BMI (OR: 1.144; 95% CI: 1.083-1.208) were independent risk factors for later development of GDM (p < 0.01). FPG level > 4.6 mmol/L was the best threshold for predicting GDM with a sensitivity of 53.89 and specificity of 70.90%. BMI >= 23.5 kg/m(2) yielded a sensitivity of 48.5% and a specificity of 73.1% for predicting GDM. FPG and BMI combined markedly enhanced the predictive capability for GDM (OR, 3.861; 95% CI: 2.701-5.520). High FPG or BMI in the first trimester, especially in combination, may predict later GDM with limited accuracy and specificity in Chinese women.