Body image research with young children has typically examined their body satisfaction and overlooked developmental theories pertaining to their emergent body-knowledge. Though existing research suggests that preschoolers do demonstrate anti-fat attitudes and weight-related stigmatisation, body dissatisfaction can be difficult to assess in preschoolers due to developmental differences in their (i) ability to perceive their actual body size accurately and (ii) make comparisons with a hypothetical ideal. We review current findings on the attitudinal component of body image in preschoolers, together with findings on the accuracy of their body size perceptions and their emergent body awareness abilities. Such an integration of the cognitive development literature is key to identifying when and how young children understand their physical size and shape; this in turn is critical for informing methodological design targeted at assessing body dissatisfaction and anti-fat attitudes in early childhood.