Internalising the consumer culture ideals of materialism and appearance has been shown to be negatively related to adults' well‐being. Similarly, adults who strive towards these ideals for extrinsic reasons, such as to improve their image or status, have been shown to have lower levels of well‐being than those who strive towards them for intrinsic reasons, such as to help others or support healthy relationships. However, to date, there is little evidence that these links exist in children. In the present research, we use new, age‐appropriate scales to test our predictions derived from self‐determination theory that being extrinsically motivated to achieve materialistic and appearance ideals will predict their internalisation, which, in turn, will negatively predict children's well‐being. An initial pilot study found that extrinsic motives were negatively related to well‐being in a sample of 150 children aged 8–11 years but that intrinsic motives were not. In our main study, we modelled materialism and appearance as indicators of a single underlying consumer culture construct, and, in a sample of 160 youths aged 8–15 years, found support for our hypothesis that being extrinsically motivated to achieve these consumer culture ideals predicts their internalisation, which negatively predicts well‐being. We discuss the possible mechanisms involved in these processes and the implications of these findings for future research. Copyright © 2014 John Wiley & Sons, Ltd.