This study attempted to determine teachers’ perspectives on the 10 attributes of the IB learner profile. The 24 participants in this descriptive case study were elementary classroom teachers ranging from kindergarten to grade 5 at an international, private, bilingual school in Ankara, Turkey during the 2011-2012 school year. A survey and semi-structured interviews were used to determine teachers’ perspectives on the clarity of assessing the learner profile attributes, the strategies used for assessing the attributes, and the classification of the attributes into four given categories. Frequency analysis established which of the learner profile attributes were perceived to be the clearest, as well as the most unclear attributes, when considering assessment. Caring was the learner profile teachers perceived to be the clearest attribute to assess, while balanced was the attribute teachers perceived to be the most unclear to assess. Frequency analysis was also used to determine into which categories each of the attributes was classified. Five common themes emerged from survey responses, and were further developed through the analysis of the semi-structured interviews as to why teachers perceived certain attributes to be more difficult, or unclear, when considering assessment. The five themes were: “subjectivity due to the abstract nature of certain attributes,” “artificial results,” attributes that are “unable to be observed,” and finally, “personal,” and “cultural” elements. Another major result of this study was that participants had different understandings regarding classification of the 10 attributes amongst themselves, as well as when compared to the classification Dr. Kate Bullock published in 2011. Supported by the literature reviewed for this research, this study suggests that the ambiguity of the learner profile attributes is due to the fact that the IB has not provided research into how and why the current 10 attributes were chosen. More importantly, the IB has not provided research about theories of values development in children throughout different age groups. It is recommended that the IB create common documents to assist with data collection and reporting on the learner profile attributes; the IB intensively train teachers on how to implement the learner profile; and the IB create a developmental continuum for each of the attributes of the learner profile.