The study explored the effectiveness of a proposed blended learning program for developing some twenty-first century skills used by EFL in-service teachers at Al AzharAl Sherif in Al-Dakahlia. The instruments of the study included the EFL teachers' twenty-first century skills knowledge test and an observation checklist of EFL teachers' performance of the twenty-first century skills. The study adopted the quasi-experimental design utilizing two groups; one group was experimental and the other was a control group. The total number of the participants in the two groups for the study was (n=60). Results of the study indicated that the experimental outperformed the control group on the post-administration of EFL teachers' twenty-first century skills knowledge test. Further, the experimental group < /em>'s performance in the twenty-first century skills surpassed that of the control group on the post-administration of the observationchecklist. This result demonstrates that the proposed program was effective in developing EFL in-service teachers' use of twenty-first century skills, and that improvement was a gradual process as a result of the training. Finally, the study also suggests that further research should be conducted related to blended learning based programs for developing other twenty-first century skills.
Key words: blended learning, twenty-first century skills, EFL in-service teachers, Al Azhar