The present study aimed to evaluate the effect of brilliant cresyl blue (BCB) stain on quality and developmental competence of mature and immature buffalo oocytes. Oocytes were exposed to BCB stain diluted in mDPBS (DPBS with 0.4% BSA) for 60 min at 38.5 º C in a humidified air atmosphere before, after maturation. The cleavage and blastocyst rates were determined. Results showed the percentage of BCB+: BCBˉ in immature and mature buffalo oocytes was 54: 45 and 70: 30 respectively. In immature oocytes percentage of embryo cleavage rate was highly significantly (P< 0.0001) increased in BCB+ than BCB oocytes. Lower cleavage rates were reported in immature BCB+(P< 0.05) and BCB (P< 0.0001) compared to control non exposed oocytes. There was no significant difference between control and BCB+ oocytes in cleavage rate but there was a significant (P< 0.05) decrease in mature BCB than control oocytes. In conclusion, BCB had a detrimental effect on immature buffalo oocytes, but had no effect on mature oocytes. Thus, it was recommended that BCB was not suitable for oocytes selection as it toxic, time and money consuming.