Objective To evaluate the safety and accuracy of C1-C2 pedicle screw placement using the 3D-printed patient-specific "pointing-drilling" guide template in clinical study.Methods From May 2012 to June 2015, 22 cases of C1-C2 instability were treated including 14 males and 8 females.Mean age was 56.3 years (range, 42-69 years).Atlas fracture occurred in 8 cases, type Ⅱ odontoid fracture in 9 cases, and old odontoid fracture in 5 cases.Duration of injury was 15-37 months (mean, 26 months).All patients sustained different degree of occipito-cervical pain or extremity sensation and motion disorders.The ideal trajactory of C1-C2 pedicle screw was designed with a baseplate which was a patient-specific complementary template for the posterior C1-C2 corresponding anatomical surface.The 3D-printed "pointing-drilling" guide template was applied for pointing the start point and drilling the trajectory during the surgery.Only 1 case was failed to perform the bilateral pedicle screw fixation and just done with the unilateral pedicle screw fixation because of the incomplete C1 posterior arch and severe unstable C1 vertebrae.The start point and direction of the ideal and actual trajectory were measured after matching the position of the pre-and posto-perative patients' cervical spine.Safety of pedicle screwing was assessed in the transverse and sagittal planes of CT scan.Results In total, 43 C1 pedicle screws and 43 C2 pedicle screws were placed.No significant differences occurred in entry point and angle deviation between the ideal and actual trajectory (P ＞ 0.05).There was no neurovascular injury during or after operation.Eighty-three screws were rated as grade 0 and 3 screws as grade 1.Conclusion 3D-printed patient-specific "pointing-drilling" guide template can greatly improve the safety and accuracy of C1-C2 pedicle screw placement and reduce neurovascular injury and other severe surgical complications.