Gesture and prosody are considered to be important precursors in early language development. In the present study, we ask whether those cues play a similar role later in children's acquisition of more complex pragmatic skills, such as politeness. 64 three- to five-year-old Catalan-dominant children participated in a request production task in four different conditions. They were prompted to request an object from either a classmate or an unfamiliar adult experimenter, with the implied cost of the request to the receiver's face thus being either high or low. Results showed that these preschool-age children used mitigating prosodic and gestural strategies to encode politeness earlier and more often than they used lexical or morphosyntactic markers, and that those cues develop incrementally during the preschool years. These findings suggest that prosody, gesture, and other body signals are an essential first step in the development of children's socio-pragmatic competence.