Difference between men and women in the treatment and outcome of acute coronary syndromes has been demonstrated with increased deaths rates in women. Treatment of ACS must be revised and related to the sex and race of the patient. The aim of this study was to introduce new copeptin cutoff levels in ACS patients depending of gender. Also, to compare copeptin to hs-cTnI, CRP levels to predict time delayed between ACS symptoms onset and admission to ED. Sixty two consecutive patients with ACS presenting to the emergency department of the National Heart Institute, Giza (Egypt) between March and June 2014, were recruited for the study. The present study involved thirty patients with unstable angina (19 male & 11 females), thirty two MI patients (18 males & 14 females) and twenty healthy subjects (10 males &10 females) on admission and after 6 hours. Results revealed significant difference between cardiac levels on admission with higher values in men on admission only for CPP, disappeared after six hours. Only copeptin levels were diagnosing on admission (higher with clear cut off levels either for men or women) compared to that of six hours (decreased and get non-significant differences). Early measurement of the combination of troponin I and copeptin may revolutionize the diagnostic accuracy and therapeutic decision-making in patients with symptoms suggestive of ACS, differentiate between UA or AMI patients on admission. Female patients require reevaluation criteria for treatment and outcome.