The present study explores Greek primary school teachers' perceptions and views on pupil diversity in the classroom environment. A large-scale survey was carried out in order to examine teachers' perceptions about pupil diversity and to identify personal and/or educational characteristics that can influence or predict these perceptions. The outcomes of the study reveal that Greek primary school teachers view diversity as a challenge more than as a barrier in teaching and learning, they can recognise at a high level the key elements of differentiated instruction as part of managing pupil diversity in their class and hold a negative-to-neutral stance on traditional curriculum implementation practices. The most influential factors and predictors of these perceptions and views are also presented and discussed.