Several predictive factors associated with adverse pregnancy outcomes in female renal recipients have been suggested. Our study aimed to determine the most important factor for prediction of adverse pregnancy outcomes in female renal recipients. We studied 41 pregnancies in 29 female renal recipients retrospectively. We reviewed pregnancy outcomes and possible predictive factors including pre-pregnancy serum creatinine (SCr), pre-pregnancy glomerular filtration rate (GFR), pre-pregnancy hypertension, pre-pregnancy proteinuria, transplantation-pregnancy interval and type of immunosuppressants. We defined an adverse pregnancy-related outcomes index (APOI) that included the following conditions: (i) preeclampsia; (ii) fetal growth restriction (FGR); (iii) prematurity before 34 wk of gestation; (iv) fetal loss (v) graft dysfunction during pregnancy or within three months from delivery. The cutoff of pre-pregnancy serum creatinine and GFR was determined by receiver operating characteristics curves for the prediction of each adverse outcome and APOI. Only pre-pregnancy serum creatinine was associated with adverse pregnancy outcome, and 1 mg/dL was determined to be a useful cutoff for the prediction of each adverse outcomes. Pre-pregnancy SCr ≥ 1 mg/dL was associated with 7.7 times increased risk of preeclampsia and 6.9 times increased risk of APOI. Pre-pregnancy serum creatinine is the most powerful predictive factor for adverse pregnancy outcomes, and <1 mg/dL may be used as a screen for successful pregnancy outcome.