Background: Anticoagulants known as blood thinners, prevent or reduce blood coagulation. Anticoagulation management is a challenge as slight change in drug concentration can result in either bleed or blood clot formation. Aim of the study: The aim was to analyse the clinical impact of pharmacist-led anticoagulation services with objectives to analyse the impact of patient counselling on knowledge, attitude, practice and medication adherence of oral anticoagulation, to identify adverse drug reactions and to assess dosage initiation and dosage adjustment of anticoagulants. Method: A prospective interventional study was conducted in clinical departments of Lourdes Hospital Kochi. Medication adherence assessed using 8 item MMAS and initial baseline knowledge about oral anticoagulants collected using a validated KAP questionnaire. Patients counselled by clinical pharmacist and followed up. Dosing of parenteral anticoagulants were monitored, ADRs identified, assessed using Naranjo scale. Results: One hundred and forty-two patients (84 parenteral and 58 oral) were enrolled in the study. Major adverse reactions were hematuria and gum bleeding. Dosing related problems were identified and intervened. Statistically significant improvement in medication adherence, knowledge, attitude and practice of patients on oral anticoagulants in addition to significant improvement in time in therapeutic range were observed. The correlation coefficient was positive (p<0.01) which interpreted that as the practice increases time in therapeutic range also increases. Conclusion: Additional Care given to the intervention group by clinical pharmacist resulted in a statistically significant improvement in knowledge, attitude, practice and medication adherence supported by improvement of time in therapeutic range, which highlights the importance of clinical pharmacist in anticoagulation management.