Background and objectives Monitoring the whole chain of events from the blood donors to recipients, documenting any undesirable or untoward effects and introducing measures to prevent their recurrence if possible, are components of haemovigilance systems. Only few sub-Saharan African countries have haemovigilance systems and there are very little data on adverse events of transfusion. Adverse events monitoring is an integral part of a haemovigilance system. Our study aimed to establish the incidence and types of adverse events of transfusions in Ghana and to identify interventions to improve effectiveness. Materials and method This prospective observational 1-year study enrolled 372 recipients of 432 transfusions in a Ghanaian teaching hospital. Vital signs were monitored at 15 and 30 minutes, and 60-minute intervals during the transfusion, then 8 hourly until 24 hours post-transfusion. Three investigators independently classified any new signs and symptoms according to Serious Hazards of Transfusion definitions. Results The adverse events incidence was 21.3% (92/432), predominantly mild acute transfusion reactions (84%). Twenty transfusions (4.6%) were stopped before completion, 60% of them for mild febrile reactions, which could have been managed with transfusion in-situ Conclusion This prospective study indicates a high incidence of adverse events of transfusion in Kumasi Ghana. The significant numbers of discontinued transfusions, suggest that guidelines on how to manage transfusion reactions would help preserve scarce blood stocks. Gradual implementation of a haemovigilance system, starting with monitoring adverse transfusion events is a pragmatic approach in resource-limited settings.