This study aimed at investigating the effectiveness of educational games on scientific concepts acquisition by the first grade students. The sample of the study consisted of (53) male and female students distributed into two groups: experimental group (n = 26) which taught by educational games, and control group (n = 27) which taught by traditional method. To achieve the purpose of the study, the researcher developed a teaching guide included eight educational games, and a test to measure scientific concepts acquisition. Results showed that there were statistically significant differences in students' scientific concepts acquisition due to the method of teaching in favor of the experimental group. Also, there were no statistically significant differences in students' scientific concepts acquisition due to the gender or the interaction between method of teaching and gender. The study recommended using educational games in teaching science in primary education.