ObjectiveTo explore the related risk factors of epilepsy after traumatic skull defect repair.MethodsThe clinical data of 72 cases patients underwent cranial three-dimensional titanium mesh repair in Neurosurgery Department of Sichuan Baoshihua Hospital from February 2010 to December 2017 were collected and followed up for 6 months, retrospectively analysed the causes and operation problems of secondary epilepsy after repair.Results21 casese (29.2%) among the 72 cases patients underwent cranioplasty were found with secondary epilepsy. Univariate analysis showed that the rate of secondary epilepsy in patients with softening lesion of gray matter, no formal antiepileptic treatment after the first operation, suspension of dural during operation and repair time of the trauma >6 months was significantly higher than that in patients without secondary epilepsy (P<0.05). Multivariate Logistic regression was used to correct the results, showing that softening lesion in the gray matter [OR=8.425, 95% CI (2.541, 27.934), P<0.001)], no formal antiepileptic treatment after the first operation [OR=0.160, 95% CI (0.050, 0.518), P=0.002], intra-operative suspended dural [OR=13.306; 95% CI (3.769, 46.976), P<0.001] and repair time of trauma >6 months [OR=6.205, 95% CI (1.705, 22.583], P=0.006] were independent risk factors of secondary epilepsy.ConclusionAfter decompression of bone flap, regular antiepileptic therapy, shortening repair time, and proper peroperative management can reduce the incidence of postoperative epilepsy.