Classroom environment plays a significant role in determining students’ level of academic achievement and enhancingtheir holistic growth. For students, the classroom is not just an intellectual space, but also a social, emotional andphysical environment. The purpose of this study is to examine the effects of classroom environment on learningEnglish as a foreign language by a group of first grade students at Secondary Schools in Gezira State in the Sudan. Thisstudy indorses the experimental approach to realize its objective. Two groups of students are classified as theExperimental and the Control group and assigned to study under two different classroom environments. TheExperimental group consists of (122) students. These are accommodated in three well renovated classrooms; while theControl group which includes (135) students are assigned to study in non-renovated schools under relatively poorclassroom environments. The two groups are taught the same English language material by teachers with similarqualifications and experiences during the first term of the academic 2016. Scores in the English Final Examination forthe two groups are compared to check the classroom environment effect on the students’ achievement. These scores aretabulated and analysed using descriptive statistics. The results reveal that there are significant differences between theachievements of the Experimental and the Control group in English in favour of the Experimental group who havestudied under favourable classroom conditions. The researcher has also explored the administrators’ and teachers’viewpoints regarding the learning environment in the study zone and its possible impact on students’ achievement inEnglish. The study ends up with some recommendations including conducting further studies on the environmentaleffect on other school subjects and on female students’ achievement.