BackgroundRecognising the substantial political weight of the United Nations General Assembly (UNGA), a UN General Assembly special session (UNGASS) and high-level meetings (HLMs) have been pursued and held for 5 health-related topics thus far. They have focused on human immunodeficiency virus/acquired immune deficiency syndrome (HIV/AIDS, 2001), non-communicable diseases (NCDs, 2011), antimicrobial resistance (AMR, 2016), tuberculosis (TB, 2018), and universal health coverage (UHC, 2019). This observational study presents a comprehensive analysis of the political and policy background that prompted the events, as well as an assessment of aims, approaches, and ultimate outcomes.Methods and findingsWe investigated relevant agencies’ official documents, performed a literature search, and accessed international institutions’ websites for the period 1990–2020. Knowledgeable diplomatic staff and experts provided additional information. Outcomes were evaluated from a United Nations perspective based on national and international commitments, and funding trends. Eliciting an effective governmental response through UNGASSs/HLMs is a challenge. However, increased international commitment was evident after the HIV/AIDS (2001), NCDs (2011), and AMR (2016) meetings. The more recent TB (2018) and UHC (2019) HLMs have received general endorsements internationally, although concrete commitments are not yet documented. Although attribution can only be hypothesized, financial investments for HIV/AIDS following the UNGASS were remarkable, whereas following HLMs for NCDs, AMR, and TB, the financial investments remained insufficient to face the burden of these threats. Thus far, the HIV/AIDS UNGASS was the only one followed by a level of commitment that has likely contributed to the reversal of the previous burden trend. Limitations of this study include its global perspective and aerial view that cannot discern the effects at the country level. Additionally, possible peculiarities that modified the response to the meetings were not looked at in detail. Finally, we assessed a small sample of events; thus, the list of strategic characteristics for success is not exhaustive.ConclusionsOverall, UNGASSs and HLMs have the potential to lay better foundations and boldly address key health challenges. However, to succeed, they need to (i) be backed by large consensus; (ii) engage UN authorities and high-level bodies; (iii) emphasise implications for international security and the world economy; (iv) be supported by the civil society, activists, and champions; and (v) produce a political declaration containing specific, measurable, achievable, relevant, and time-bound (SMART) targets. Therefore, to ensure impact on health challenges, in addition to working with the World Health Assembly and health ministries, engaging the higher political level represented by the UNGA and heads of state and government is critical.