A blog is an innovative web tool which has an immense potential to enhance language abilities. As one of the ways to enhance foreign language learning is collaboration and interaction, the present study is an attempt to find out if blogs can be used to foster language learners' comprehension through collaborative book reading. To this end, 62 Iranian EFL students studying at the university were selected as the participants. After they were indicated to be homogeneous regarding their reading comprehension, they were divided into two groups. Both groups were instructed for three months. The control group read story books as their supplementary reading activity individually, but the experimental group used the teacher's blog to read the same short stories assigned to the control group but with collaboration of their peers in a virtual environment. The participants' performances in the reading comprehension post-test revealed that joint reading through blogs can foster language learners' comprehension. Besides, it was concluded that using blogs, females had more improvement in their reading comprehension than male students.