Drug-related problems (DRPs) in a pharmacist-managed anticoagulation clinic (AC) have not been extensively studied. We aimed to characterize the DRPs in a pharmacist-managed AC, identify the factors associated with the solved status of DRPs, and analyze the secondary outcomes, including the safety and efficacy of AC service. The patients receiving services at a pharmacist-managed AC in a medical center for the first time from March 2019 to August 2020 were reviewed retrospectively. The DRPs were retrieved from a self-developed Intelligent AC Service System and classified according to the Pharmaceutical Care Network Europe Foundation v9.0 classification system. Logistic regression models were performed to identify the potential factors associated with the solved status of DRPs. A total of 78 direct oral anticoagulant (DOAC) and 34 warfarin users were included. The major types of DRPs identified at the initial service were adverse drug events (ADEs) (68.4%) and untreated symptoms or indications (14.8%) in the DOAC group, and ADEs (51.6%) and suboptimal effect of drug treatment (38.7%) in the warfarin group. The rates of totally solved DRPs were 56.8% and 51.6% in the DOAC and warfarin groups, respectively. According to the multivariable analysis, receiving AC services 3 times or more in 180 days (OR 3.11, 95% CI 1.30-7.44) was associated with the totally solved status of DRPs in the DOAC group, but no relevant factor was identified in the warfarin group. The secondary outcomes showed that DOAC users demonstrated fewer thromboembolism events, major bleeding, and bleeding-related hospitalizations after AC services, whereas the warfarin users increased percentage time in therapeutic range (TTR% 55.0% vs. 74.6%, P = 0.006) after AC services. These findings may be utilized to develop DOAC and warfarin AC services.