Live and motile sperm is usually observed after fertilization in the culture dish, but interestingly dead and immotile sperm was sometimes observed. However, the association of sperm death after fertilization in the culture dish and IVF outcomes have not yet reported. In this study, we investigated relationship association of IVF outcomes and sperm death in the culture dish after fertilization on conventional IVF. Retrospective cohort study. We analyzed 472 cycles from patients aged under 40 years undergoing conventional IVF from January 2012 to December 2013. After fertilization, the patients were classified depending on sperm condition in the culture dish into two groups : group A (n=435): high percentage of the living sperm with hyperactivated motility, group B (n=37): more than 80% of immotile with dead sperm in the culture dish. We compared IVF outcomes between two groups. There were no differences in patients age (group A; 35.12±2.9 vs. group B; 35.16±3.1, p=0.94), number of oocytes (9.2±5.4 vs. 7.8±5.5, p=0.13) and sperm counts (53 x 10ˆ6/mL±26.62 vs. 50.13 x 10ˆ6/mL±34, p=0.53). And also fertilization rate did not differ between two groups (72.8% vs. 69.6%, p=0.32). However, the clinical pregnancy rate in group B was significantly higher than group A (56.3% vs. 75.6%, p=0.02). In this study, dead sperm group showed significantly higher pregnancy rate compared with living sperm group. We suppose that high percentage of dead sperm means good quality sperms burn out the limited amount of nutrients in the culture dish. Therefore, high percentage of sperm death after fertilization on conventional IVF could be a good prediction of IVF outcome.