The 30th workshop of the HTLV European Research Network (HERN) was held in Madrid on September 15–16, 2023. Over fifty researchers from Europe and America convened for a two-day conference to update and discuss basic science, epidemiology, clinical management and therapeutics for patients with HTLV-1 infection. Scientific topics addressed included new estimates for HTLV-1 in Europe; impact of antenatal screening on mother-to-child HTLV-1 infections; new insights into the molecular epidemiology of HTLV-1; reports of elite controllers for HTLV-1 infection; role of antiretrovirals as HTLV-1 pre-exposure prophylaxis; and prospects for a HTLV-1 vaccine. The group agreed to submit a formal request to WHO for increasing the global surveillance and awareness of HTLV-1. This viral infection is a potentially life-threatening, neglected condition with neither treatment nor vaccine. At this time, expanding HTLV-1 screening is the most effective way to reduce viral dissemination.