Background: Atrial fibrillation (AF) increases risk of stroke 5-fold. Carotid artery disease (CD) also augments the risk of stroke, yet there are limited data about the interplay of these 2 diseases and clinical outcomes in patients with comorbid AF and CD. Hypothesis: Among patients with both AF and CD, use of rivaroxaban when compared with warfarin is associated with a lower risk of stroke. Methods: This post hoc analysis from ROCKET AF aimed to determine absolute rates of stroke/systemic embolism (SE) and bleeding, and the efficacy and safety of rivaroxaban compared with warfarin in patients with AF and CD (defined as history of carotid occlusive disease or carotid revascularization [endarterectomy and/or stenting]). Results: A total of 593 (4.2%) patients had CD at enrollment. Patients with and without CD had similar rates of stroke or SE (adjusted hazard ratio [HR]: 0.99, 95% confidence interval [CI]: 0.66-1.48, P = 0.96), and there was no difference in major or nonmajor clinically relevant bleeding (adjusted HR: 1.04, 95% CI: 0.88-1.24, P = 0.62). The efficacy of rivaroxaban compared with warfarin for the prevention of stroke/SE was not statistically significant in patients with vs those without CD (interaction P = 0.25). The safety of rivaroxaban vs warfarin for major or nonmajor clinically relevant bleeding was similar in patients with and without CD (interaction P = 0.64). Conclusions: Patients with CD in ROCKET AF had similar risk of stroke/SE compared with patients without CD. Additionally, there was no interaction between CD and the treatment effect of rivaroxaban or warfarin for stroke prevention or safety endpoints.