There have been various Haemophilia Treatment Centres (HTCs) set up worldwide with innovative blood factor stewardship programs. Pharmacists have been an extended part of stewardship programs providing daily rounds with haematologists, treatment plan modifications, and dosage adjustment recommendations. The Haemophilia Treatment Centres in Malaysia contain the Haemophilia Medication Therapy Adherence Clinic (HMTAC), which recruits adolescent and adult populations. There have not been any adherence studies conducted on pharmacist-steered HMTAC since initiation. The current research generates baseline data to produce treatment plans and intervention measures needed for therapy optimisation in the Malaysian population. This study also explores the relationship between medication adherence, bleeding rate, and comorbidity. This cross-sectional study involved retrospective and prospective data collection using the Validated Haemophilia Regimen Treatment Adherence Scale–Prophylaxis (VERITAS-Pro) in Ampang Hospital. The retrospective data collection included reviewing patients’ medical records, bleeding diaries, and VERITAS-Pro questionnaires pre-enrolment to HMTAC. Meanwhile, the prospective data collection was the VERITAS-Pro questionnaire administration post a minimum of three months after enrolment. The inclusion criteria were patients with severe haemophilia A and B with ages ≥18 years with self-administered prophylactic regimens for a minimum period of three months. There were six (5.8%) nonadherent participants, and 97 (94.2%) adhered to the preventive treatment. The subscale dosing and remembering and the total score of the VERITAS-Pro post-HMTAC showed a significant association with ABR. There was a significant mean reduction in the post-HMTAC compared to the pre-HMTAC score for the total score and subscales timing, remembering, skipping, and communicating. There was a significant association between the post-HMTAC adherence status and ABR. It can be concluded that the HMTAC service pioneered by the pharmacists in the National Referral Centre of Haematology is efficient in significantly improving the VERITAS-Pro scoring and then translating it into a high medication adherence rate. This study also highlights a significant correlation between post-HMTAC scores on their adherence with ABR and comorbidities.