We present a theoretical-conceptual proposal for communicative intentionality and meaning. We aim to offer un operational definition of 'communicative act' and, in the last analysis, to guide empirical studies of baby-adult communication. Firstly, we present the theoretical-conceptual ideas basing our vision of communicative intentionality and meaning as gradual and observable processes, in a baby-adult interaction frame. From this proposal, we derive un operational definition of 'communicative act', which refers to a set of observational indicators of communicative intentionality and meaning. Finally, through examples selected from un observational/longitudinal study of three motherchild couples, from birth to the age of eighteen months, we illustrate different levels of intentionality and meaning in babies' communicative acts