Food neophobia and picky/fussy eating behavior are presented as the two main forms of children's food rejections which are responsible for a reduction of their dietary repertoire. We review the key factors, presented in the literature, that are involved in food rejections during childhood. We first consider a range of " cognitive factors " , such as food perception, mental representations, categorization of food items, and emotions and feelings toward food. Next we focus on " social and environmental factors " , as these might also significantly influence and modulate children's food rejections. We then summarize the findings to provide a comprehensive view of the factors involved in children's food rejections. Finally, we discuss the need for future studies on food rejections, regarding (i) the distinction between food neo-phobia and picky/fussy eating, and (ii) the potential link between food categorization abilities and children's food neophobia and pickiness.