OBJECTIVES: To explore the reasons for not initiating or stopping VKA treatment in patients with atrial fibrillation (AF) at moderate to high risk of stroke, along with the reasons for considering some patients on VKA to be “difficult-to-manage”. METHODS: A retrospective chart review was conducted with 39 Canadian and 29 Swedish physicians participating. Three cohorts of AF patients at moderate/high stroke risk (CHADSscore ≥2 points) were examined: a) VKA naïve, b) had stopped VKA treatment or c) receiving VKA and considered “difficult-to-manage”. Variables retrieved were: sociodemographic data and comorbidities, variables related with AF and its management and the reasons why patients a) never received VKA, b) stopped VKA, or c) were considered “difficult-to-manage”.  RESULTS: In Canada, 187 patients were included (naïve/stopped/difficult-to-manage 62/42/83), 58.3% males, mean (SD) age 78.4 (8.9) years. In Sweden, 152 patients were included (naïve/stopped/difficult-to-manage 39/24/89), 68.4% males, mean (SD) age 76.0 (8.8) years. For VKA naïve patients, the most common reasons for not initiating VKAs were: Canada - transient nature of AF (40.3%), fall risk (30.6%); Sweden - patient refusal to take VKAs (28.2%), fall risk (1.8%), bleeding risk (1.8%). For patients who stopped VKA treatment, the most common reasons for discontinuation were: Canada - bleeding event (23.8%), patient unable to comply with therapy/monitoring (19.0%); Sweden - bleeding event (45.8%), clinical event (18.2%). For patients on VKA the most common reasons for being considered “difficult-to-manage” were: Canada - concomitant chronic diseases (55.4%), poor INR control (54.2%); Sweden - difficulties in following dietary/behaviour advice (24.7%), concomitant chronic diseases (22.5%). CONCLUSIONS: In Canada and Sweden the reasons for not initiating or stopping VKA treatment in AF patients were similar, with fall risk and bleeding events being commonly cited. The main reasons for considering a patient on VKA as “difficult-to-manage” are mainly related to concomitant diseases in both countries.