Anticoagulant therapy during the acute phase of non-ST elevation acute coronary syndromes (NSTE-ACS) is strongly recommended by current international guidelines. Evidence supporting the use of anticoagulant therapy in the early phase of NSTE-ACS however, is based on dated trials mostly performed in the nineties and recent randomised clinical trials (RCTs), performed during the last 15 years, clearly evidence a dichotomy in the investigation of antiplatelet and anticoagulant strategies. Many innovations have since occurred in the diagnosis and management of NSTE-ACS. Since a RCT evaluating the efficacy of anticoagulant therapy versus placebo in a contemporary setting of NSTE-ACS management is lacking, we provide a systematic review of 1) the randomised data for ATT in the early phase of NSTE-ACS; 2) modern international guidelines, and 3) contemporary clinical practice data. The results are analysed and potential treatment and research strategies are proposed.