This paper studies fertility intentions and their outcomes, analyzing the complete path leading to fertility behavior according to the social psychological model of Theory Planned Behavior (TPB). We move beyond existing research using graphical models to have a precise understanding, and a formal description, of the developmental fertility decision-making process. Our findings yield new results for the Italian case which are empirically robust and theoretically coherent, adding important insights to the effectiveness of the TPB for fertility research. In line with TPB, all intentions’ primary antecedents are found to be determinants of the level of fertility intentions, but do not affect fertility outcomes, being pre-filtered by fertility intentions. Nevertheless, in contrast with TPB, background factors are not fully mediated by intentions’ primary antecedents, influencing directly fertility intentions and even fertility behaviors.