BACKGROUND : To evaluate safety and efficacy of the new generation Derivo embolization device in complex ruptured (RIA) and unruptured (UIA) intracranial aneurysms. METHODS : Retrospective analysis of 32 patients with complex RIAs and UIAs treated with Derivo at our hospital from Nov.2015 to Dec.2018. Clinical safety was defined as absence of death, transient attack, absence of minor and major stroke, and Derivo associated hemorrhage. Treatment efficacy was assessed angiographically (DSA) immediately after treatment and at 6 month follow-up according to the O'Kelly Marotta (OKM) grading scale (A=total filling to D=no filling; prolongation of stasis 1=arterial to 3=venous phase). RESULTS : 32 patients with 39 aneurysms were treated with 42 Derivos. In 5 aneurysms additional coiling was performed. Deployment was technically successful in all cases. Two patients developed a procedure related minor stroke (one transient). In 1 patient bleeding due to an inflammatory aneurysmatic wall process occurred 20 days after retreatment and in 1 patient a stroke due to instent thrombosis occurred when dual platelet inhibition (PI) was switched to permanent single PI 12 month after FD treatment. No treatment related deaths were observed. Initial DSA revealed OKMD,n=3; C,n=6; B,n=5; A,n=25. Six-month follow-up for DSA and clinical evaluation was available in 20/32 patients (62.5%), 26/39 aneurysms (66.7%) and revealed 73.1% complete and 3.8% subtotal occlusion (OKMD:19/26, OKMC3:1/26). CONCLUSIONS : Treatment of complex RIAs and UIAs with the new generation Derivo appeared to be safe and effective in this single centre case series for ruptured and unruptured intracranial aneurysms. Immediate DSA revealed a significant flow modulation; and 6-month follow-up showed a high occlusion rate.