This research aimed at investigating the effect of using flipped classroom on developing most necessary essay writing skills and attitude towards writing in English for 1^st year Cairo Higher Institute for Languages and Interpretation students. Participants of the research were randomly selected and divided into two groups (40) for the experimental group and (40) for the control group. The research prepared and employed an essay writing skills' test and a writing attitude scale. The necessary essay writing skills for 1^st year Cairo Higher Institute for Languages and Interpretation students were determined through the use of a checklist approved by a jury of specialists in teaching EFL. During the experiment, the experimental group received instruction through using flipped classroom, while the control group received regular instruction. The experiment lasted for two months. The quasi experimental design was followed. The statistical analysis of the obtained data from the administrations of the test confirmed the effect of flipped classroom on developing essay writing skills and attitude towards writing in English for 1^st year Cairo Higher Institute for Languages and Interpretation students. Thus, the aim of the research was achieved as using flipped classroom showed a large effect size on developing the essay writing skills and attitude towards writing in English for the participants of the experimental group. Based on the results, it was recommended that instructors should give due attention to the development of essay writing skills and attitude towards writing in English for university students through flipped classroom. In addition, using flipped classroom in developing other language skills was suggested.