This study aims at presenting the opinions of elementary mathematics teachers on the incorrect problem sentences posed by the seventh grade students, with regard to addition of fractions. The study was conducted with 10 elementary mathematics teachers located in the city center of Erzurum province. Data for the study have been collected in two stages. At the first stage, the Problem Posing Test, prepared for addition of fractions, was applied to the seventh grade students. At the second stage, data were collected by applying the interview form, which includes six incorrect problems, to the teachers. The data obtained from both stages of the study has been analyzed through categorical analysis technique, listed under the content analysis types. The results of the study show that the elementary mathematics teachers experienced difficulty in identifying the errors, showing a lower rate of success in problem sentences that include more than one error and made different errors in explaining the errors.