The peer effect is a relevant issue in studies on consumption habits and consumers’ behaviour. Indeed, the extant literature shows that peers and siblings affect individual decisions and choices, as people generally follow peers’ and siblings’ examples. In other words, people imitate their peers. Starting from the existing theoretical models and empirical evidence that suggest a relevant impact of peers on one's decisions, this article analyses how the presence and the gender of siblings affects one's consumption of phone services. I consider a sample of 500 European undergraduate students. In order to isolate the peer effect, I restrict the analysis to the use of the phone for talking with friends. The results show highlight a strong sibling effect, whose magnitude and whose sign depend on both the gender of the siblings and on that of the interviewee.