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Objective:To relate seminal plasma reproductive and metabolic hormone profile to both semen freezability and post-thaw semen characteristics.Methods:Semen was collected from each Arabian stallion (N=16) for five consecutive weeks and evaluated before conducting this study. Seminal plasma was collected during semen processing for measuring leptin, insulin, Insulin like growth factor-I (IGF-1), cortisol, testosterone, estradiol and thyroid hormones. Stallions were classified into good (N=10) and poor freezer (N=6). Semen post-thaw motility (%), viability index, membrane and acrosome integrity (%) were also evaluated.Results:Good freezer stallions had significantly (P=0.0001) high cortisol, estradiol, insulin, IGF-1, T3 and T4, but significantly low leptin (P=0.003). Post-thaw sperm viability index (P=0.0001), membrane integrity (%) (P=0.002) and motility (%) (P=0.0001) at 0, 1, 2 and 3 h of good freezer stallions was significantly high compared to poor freezers. Testosterone, insulin and IGF-1 in seminal plasma of good freezer stallions had significant (P<0.01) positive correlation with sperm post-thaw viability index but estradiol and insulin in seminal plasma of poor freezers correlated with sperm post-thaw viability index. Within good freezer stallions, testosterone in seminal plasma correlated positively with both viability and acrosome integrity but within poor freezer stallions it had a negative correlation with both of them. Individual variation existed between animals and significantly affected seminal plasma hormones and semen post-thaw characteristics.Conclusion: Good freezer stallions could be selected depending on assaying seminal plasma hormones. Both estradiol and IGF-1 could be used as semen extender supplementation to improve sperm post-thaw motility, viability and acrosome integrity.