Blogs have become one of the most successful tools of the Web 2.0 because of their ease of use and the availability of open platforms. They have quickly spread in the education field thanks to the many attractive qualities that have been attributed to them, such as collaboration, communication, enhancing of professional writing, and the improvement of information-gathering skills. However, many of the studies that have addressed this issue were not based on an empirical research, and therefore they are unreliable. On the other hand, the studies that do have conducted an empirical research have usually relied on participant self-reported data (surveys, interviews, and contents of blogs), which can significantly bias the positive results usually reported on the use of blogs. Another source of bias and inaccuracy in the reported results is that most of the studies lacked control group, i.e they do not follow an experimental design. The purpose of this review is to examine the current state of the studies related to the evaluation of the blog effects in the education field. The methods to select the studies and perform the corresponding analysis have followed a qualitative systematic approach. The selection has been restricted to empirical and peer-reviewed studies published between January 2011 and June 2013. The findings have been integrated and compared using the Grounded Theory, giving rise to a set of categories that have structured the results of the review.