Abstract The study explored the effectiveness of a proposed hybrid formative assessment program for developing EFL speaking skills of preparatory stage pupils. The instruments of the study included EFL speaking skills checklist to determine the most important sub-skills of speaking skills,  EFL speaking skills test to measure pupils' speaking skills (pre-post), and  EFL speaking skills scoring rubric to assess pupils' speaking skills on the pre and post EFL speaking skills test. 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 there was a statistically significant difference between the mean scores of the experimental group and the control group on the post-administration of the EFL speaking skills test in favor of the experimental group. This result demonstrates that the hybrid formative assessment program was effective in speaking skills of preparatory stage pupils and that improvement was a gradual process as a result of using hybrid formative assessment program. Finally, the study also suggests that further research should be conducted related to hybrid formative assessment based programs for developing other language skills. Key words: Hybrid Formative Assessment, Speaking Skills, EFL Preparatory Stage Pupils