Abstract: Effective methodologies for oocyte cryopreservation are currently lacking. Therefore this study aimed to examine the meiotic competence and DNA damage of immature porcine oocytes following cryoprotectant exposure and vitrification. In the first experiment, porcine oocytes were exposed to 4 cryoprotectants for 1 min before in vitro Maturation (IVM). The cryopreservatives used were: (1) 40% ethylene glycol [40% EG], (2) 20% EG and 20% glycerol [20% EG/GLY]; (3) 20% EG and 20% propylene glycol (PG) [20% EG/PG]; (4) 20% EG and 20% dimethyl sulphoxide [20% EG/DMSO]) In the second experiment, the porcine oocytes were vitrified with 40% EG, 20% EG/GLY, 20% EG/PG or 20% EG/DMSO before IVM. After cryoprotectant exposure or vitrification, the oocytes were cultured in the maturation medium for 44 h. As a control, oocytes were cultured for 44 h without cryoprotectant exposure and vitrification. In the third experiment, immature oocytes were incubated with 7.5 μg mL-1 cytochalasin B for 38.5°C for 30 min, followed by vitrification and culture for 44 h. The meiotic status and DNA fragmentation of the oocytes were examined after IVM. As a cryoprotectant, 20% EG/GLY was superior to 20% EG/PG and 20% EG/DMSO, with respect to the meiotic competence and DNA fragmentation of oocytes. The percentage of DNA fragmentation was significantly lower in oocytes with cryoprotectant exposure and vitrification than in control fresh oocytes, irrespective of the treatment of cytochalasin B. These results indicate that the meiotic competence of porcine oocytes is damaged by cryoprotectant exposure and the competence of vitrified oocytes is not improved by pre-treatment of oocytes with cytochalasin B before vitrification.