Background:Petroclival meningiomas (PCMs) are technically challenging lesions.Although the standard retrosigmoid approach is one of the most effective approaches,this route may have some limitations for the tumors extending into the supratentorial region and middle cranial fossa.We provide a modified surgical technique called retrosigmoid-transtentorial approach (RTTA) to solve these problems.The feasibility and efficacy of the RTTA were studied,by analyzing neurological outcomes and considerations of surgical strategies.Methods:We analyzed 64 of 71 PCM patients (90.1％).All 64 patients had epicenter of tumor in the posterior fossa with varying degrees of extension into the supratentorial area and/or the middle fossa.A conventional retrosigmoid craniotomy was performed following which the tentorium was incised from the attachment of tumor toward the free edge,which improved exposure to the petroclival region by offering additional operative room without resection of the adjacent part of the petrous bone.Results:The rate of gross total resection was 71.9 ％.There was no incidence of intraoperative death.One patient died in the postoperative phase.The postoperative permanent morbidity rate was 25.4 ％.Follow-up was done with the mean time of 60.7 ± 47.5 months.There were 6 recurrence,8 progression and 7 death cases and the mean KPS score was 83.2 ± 13.4 in the last follow up.Conclusions:The RTTA achieves the goal of applying a safe,quick,uncomplicated,and lesser invasive access to the petroclival region which is indicated for tumors located in the posterior fossa with some extension into the supratentorial area and/or the middle fossa.