T he aim of this piece of research was to explore the effect of three different environments of blended learning compared to traditional learning on EFL university students' achievement and attitudes in a Computer-Assisted Language Learning and Specialized Technology Course. A hundred EFL juniors at the Faculty of Education, Kafr El-Sheikh University participated in this study. They were taught the set course by merging lectures with complementary tasks, assignments and activities on a Web site and further illustrations and discussions on Facebook. Participants were free to choose the environment of learning to adopt during their study. At the end of the academic semester, the results of the formal exam held by the Faculty were analyzed statistically by using One-Way ANOVA to attain inferences about the effect of learning environment on achievement. Participants were given a questionnaire for eliciting their impressions and self-assessment of the blended learning they received. Results indicated the claim that learning environment affects achievement was not true. However, attitudes and preferences of blended learning environments varied.