T he current study aimed at exploring the effectiveness of affordance-based teaching on EFL students' general English language performance. Sixty four freshmen in two classes of the preparatory year at the Northern Borders University participated in this study. One class with 31 students was assigned to the experimental group while the other class with 33 students was assigned to the control group. Students in both classes were all in literary path, registered in English 1 course (Code: 1001101). Affordance-based teaching that utilizes lesson contingent affordances and various learning opportunities offered by language learning tasks, was used with the students of the experimental group whereas, those of the control group were taught in the usual way. A pre-post general English language test was used to assess participants' general English language performance before and after the intervention. Results revealed that experimental group students outperformed their counterparts of the control group in the posttest of general English language performance. Based on the results attained, some recommendations were made; A change is needed in EFL teachers' practices, from teaching to managing learning and from teaching pre-planned specific teaching points to identifying and managing learning opportunities. Instead of basing their lesson plans on specific learning outcomes, they should plan for richness of opportunity. In addition, EFL teachers should overcome their fear of going off script and they should be prepared to cope with unexpected classroom events and help their students to act on them.