This study aimed to explore the impact of using flipped classroom strategies of teaching mathematics (Calculus course) at Umm Al-Qura University on students' achievements. A final test was used for this study to identify the differences between two groups of students, experimental group that were taught by using flipped classroom strategies and control group that was taught by traditional teaching methods such as the lecture. Fifty university male students from Umm Al-Qura University were involved for the study and their performances evaluated after the implementation of using flipped classroom strategies of teaching during the 1^st semester of 2019. An independent T- test was used to identified the differences of mean scores of the two groups of students.The results indicated that there were statistical differences between experimental group and control group in the final test scores for experimental group that were taught by this strategy. The flipped classroom strategy marginally improved the scores those learners.