Abstract Background and Aims Atrial fibrillation (AF) is common in patients with chronic kidney disease (CKD). It is well known that CKD in AF patients increases the risk of thromboembolic complications, and also bleeding. However, there is lack of safety and efficacy data of oral anticoagulation (OAC) in patients with advanced CKD. Method The FinACAF study includes data from 411 000 patients covering all Finnish AF patients from 2004 to 2018. Using national unique personal identification numbers, individual patients’ data from several registries and laboratory databases were linked together. The inclusion criteria of this study were all patients 20 years or older with a new-onset, non-valvular AF between 2010 and 2018 and a measured estimated glomerular filtration rate (eGFR) within the proximity of the AF diagnosis. Risk of stroke in patients with CKD stages 4-5 (eGFR < 30 ml/min/1.73 m2) was evaluated. Patients on dialysis and those with functioning graft were excluded. Participants were followed for the occurrence of ischemic stroke (IS) until December 31st 2018 or until death or until the OAC exposure reached a maximum duration of 730 days, whichever came first. The follow-up period was capped at 730 days due to the limited number of patients with direct oral anticoagulation (DOAC) exposure exceeding 730 days. Hazard ratios [95% confidence intervals (CI)] comparing different OACs or no OAC were derived from the Cox regression model. Results The study cohort included 4148 patients. The mean (SD) eGFR was 21.5 (6.7) ml/min/1.73 m2. 1940 patients had no OAC, 1658 patients had warfarin and 550 patients had any DOAC (396 apixaban, 121 rivaroxaban, 17 dabigatran and 16 edoxaban). During the follow-up 146 patients (3.5%) had ischemic stroke. Compared to patients with no OAC (reference) HRs were 0.42 [95% CI 0.30-0.59)] for the patients with warfarin and 0.28 [95% CI 0.01-0.52)] for the patients with DOACs. Cumulative hazards for ischemic stroke are shown in the Figure. Conclusion Among patients with incident AF and advanced CKD, the risk of stroke was lowest in patients with DOACs and the worst in patients with no OAC. Warfarin users were positioned in between these two groups. Further analysis is needed to evaluate also the safety of different OACs in our cohort.