The present study aimed at investigating the effect of a project based program on developing EFL conversation for primary school students. Literature and related studies dealing with project based learning in EFL teaching and conversation were reviewed. A list of conversation components was prepared by the researcher as a guide for the design of the instruments. In addition, a pre/post conversation test was designed and a conversation rubric was adapted. Then, the researcher designed the proposed program taught to a third year primary class (n=30). Students' ages ranged from (9-10) years old. Students were submitted to a pre/posttest and their conversation performance was evaluated by two raters in the light of the designed rubric. The study results revealed that the project based program is significantly effective in developing primary stage students' EFL conversation.