A retrospective study was conducted to evaluate and compare the clinical and radiological outcomes of one-stage fibular impaction allografting and vascularized greater trochanter flap autografting for the treatment of bilateral osteonecrosis of the femoral head (ONFH). Patients who underwent one-stage aforementioned hip-preserving surgeries due to bilateral ONFH were retrospectively reviewed from January 2008 to December 2013. Sixty-nine patients (138 hips) with a mean age of 31.5 years and mean follow-up of 7.0 years were included. Hips that underwent fibular impaction allografting and vascularized greater trochanter flap autografting were assigned as group A and group B, respectively. Harris Hip Score (HHS) and Visual Analogue Scale (VAS) were used for clinical evaluation, and a series of X-ray images were used for radiological assessment. For inter-group analysis, the paired t test was used for continuous data, and the Wilcoxon rank sum test was used for non-parametric data, while the Mann-Whitney U test was used for intra-group analysis. The HHS and VAS in both groups A and B had a substantial advancement when compared with the preoperative level (p < 0.01). Fibular impaction allografting can achieve more pain relief (p < 0.01), though no clinical difference was found in terms of minimal clinically important difference (MCID < 10 points). Group A showed better radiological results than group B (p = 0.04). It was discovered that the appropriate indication for each procedure was patients with Association for Research on Osseous Circulation (ARCO) stages II and III, respectively. One-stage hip-preserving surgeries for the management of bilateral ONFH could obtain good medium and long-term outcomes. It was recommended that fibular impaction allografting is more suitable for patients in ARCO stage II, while for patients in ARCO stage III, vascularized greater trochanter flap autografting is a better preference. Retrospectively registered.