The 2030 Agenda for Sustainable Development of the United Nations calls upon all signatory countries to localize its goals through National and Regional Sustainable Development Strategies (SDS). As in Italy the SDS constitute the framework of the Strategic Environmental Assessment (SEA) of Plans and Programmes (P/P), the question arises as to whether the SEA can represent a fundamental tool for SDS. Although the mutual relationship between 2030 Agenda goals and SEA is recognized in the literature, there is a lack of focus on SDS and SEA. The SEA monitoring system is an essential instrument to redirect P/P trajectories, although it represents a constant weakness of the SEA process. Opening a discussion about the relationship between SDS and SEA, the present contribution aims at assessing SEA monitoring potential in mediating the 2030 Agenda SDS’s objectives into P/P. To this end, the study delves into the SEA monitoring structure through a qualitative and comparative approach, the feasibility of which is illustrated by an application to a set of spatial plans. Results show both good potential and the criticalities of the SEA monitoring system, which allow us to outline practical inputs to update SEA monitoring guidelines and new paths to foster the mutual relationship between the SDS and SEA.