The positive effect of strontium ions on sperm motility, capacitation and acrosome reaction has been demonstrated in the mouse, human, guinea pig and hamster. In the present study, the effect of strontium ions on the viability and acrosome morphology ofboar spermatozoa, and on the fertilization and development after the microinjection of strontium ions-treated spermatozoa into porcine oocytes was evaluated. The results demonstrated that strontium ions are likely to affect the fertilizing capacity of spermatozoa in the pig positively.