It is now well recognized that the presence of early pregnancy factor (EPF) can signify the occurrence of fertilization, continuation of pregnancy and the existence of a viable embryo. With this in view, a study was undertaken to observe the potential of EPF as a marker in assessing embryo viability in cases complicated with vaginal bleeding during early pregnancy. The results indicated that the sensitivity of EPF as a marker in predicting threatened or missed abortion was 78.9% and the specificity 95.6%. The positive predictive value was observed to be 93.8% and the negative predictive value 84.6%. Our studies have shown that since EPF is present in viable but absent in non-viable pregnancies, it could be a useful marker of prognostic value in threatened abortions.