Several studies have shown the deleterious effects of energy drinks, containing taurine and caffeine, on cardiac health. This study aimed to examine synergistic effect of taurine and caffeine on platelets and haemostasis because platelet hyperactivity is a known predictor of cardiovascular diseases. Blood from twelve healthy volunteers aged 18 – 60 years was incubated with 500 µM taurine and 700 µM caffeine individually or together. Platelet activity was evaluated using platelet aggregation assays induced by ADP and collagen, and, haemostatic function by coagulation profile testing, glucose, lipid profile and inflammation marker C- reactive protein assessment (CRP). The optimal time and doses of taurine and caffeine required to inhibit platelet hyperactivity in vitro were established. A combined action of lower doses of taurine and caffeine (T+C) inhibited platelet aggregation, induced by ADP and collagen, greater than taurine or caffeine individually (p < 0.05). Taurine and T+C increased prothrombin clotting time (PT) significantly (p < 0.05), while caffeine alone decreased PT (p < 0.05). Caffeine alone increased CRP (p < 0.05). No significant change was observed in lipid parameters. These data support our hypothesis that, synergistically lower concentrations of taurine and caffeine, found in much higher concentrations in energy drinks, may be instrumental in reducing platelet activity and prolongation of clot formation.