The aim of this study is to analyze the mistakes that have been made in the group theory underlying the algebra mathematics. The 100 students taking algebra math 1 class and studying at the 2nd grade at a state university in Istanbul participated in this study. The related findings were prepared as a classical exam of 6 questions which have been presented by 3 academic members working at the same university and these questions were presented to the students accordingly. After findings were put into codes as Correct/Wrong answers, solutions coded as "Wrong" were analyzed according to the content analysis method. Classifying the mistakes made in the solutions by students, suggestions about how to rectify these mistakes were carefully offered.