Objective To analyze the risk factors for bone resorption after cranioplasty with autogenous bone flaps.Methods A retrospective analysis was performed on the clinical data of 178 patients (involving 201 autogenous bone flaps) with cranial defect who underwent cranioplasty with autogenous bone flaps in the Department of Neurosurgery in Linyi People's Hospital from January 2001 to December 2012. According to the postoperative computed tomography features, a bone flaps resorption grading was made to investigate the relationship of different risk factors with different grades of bone flap resorption.Results There were no significant difference in the grading of bone flap resorption between patients with different sexes, repair times, and sizes of bone flaps (P>0.05). The mean age of patients decreased with the increase in bone resorption grade. However, there was no significant difference in mean age between the different bone resorption grade groups (P>0.05). The bone resorption grade was correlated with the location of bone defect (P<0.05) and the severe bone resorption always occurred in the temporal and frontotemporal regions. The autogenous bone flaps with fracture (broken into 2 or 3 fragments) had a significantly higher incidence of severe bone resorption than those without fracture (P<0.05). For the patients with hydrocephalus, the patients who underwent the ventriculoperitoneal shunt had a significantly higher incidence of bone flap collapse than those who did not undergo the ventriculoperitoneal shunt (P<0.05).Conclusions The bone resorption grade after cranioplasty with autogenous bone flaps is not correlated with sex, age, repair time, and the size of bone flaps. The bone resorption grade is correlated with the location of bone defect, and severe bone resorption is commonly seen in the temporal and frontotemporal regions. The bone flaps with fracture have a higher incidence of severe bone resorption than those without fracture. The patients who undergo the ventriculoperitoneal shunt due to hydrocephalus are prone to having bone flaps collapse.