African swine fever (ASF) has re-emerged in Spain after more than three decades of the country being free of the disease, with the first confirmed cases reported on 28 November 2025 in two wild boars found dead in the metropolitan area of Barcelona (Catalonia). The outbreak, described in Veterinary Record, has so far remained confined to wild boar populations, but it represents a significant epidemiological threat to both the Spanish and European pig sectors. Authorities established an infected zone with a 20 km radius, including a 6 km high-risk core area covering 95 municipalities where wild boar populations coexist closely with human activity. Intensive surveillance and control measures were rapidly implemented, including systematic carcass searches, population control, strengthened biosecurity and monitoring of domestic pig holdings. As of early March 2026, 216 PCR-positive wild boar cases had been detected, while more than 1700 animals tested negative through active and passive surveillance, and no infections have been identified in domestic pigs to date. Genetic analysis confirmed a genotype II ASF virus belonging to a newly defined lineage, highlighting the complexity of the virus’s global epidemiology and suggesting that long-distance spread may be linked to human-mediated activities and wild boars exploiting anthropogenic food resources. Researchers from our WEH-SEFaS Group contributed to the investigation and early response to the outbreak, with pathologist R. Velarde contributing to diagnosing the first case. This situation underlines the importance of continued vigilance, strict biosecurity and rapid reporting of suspected cases to prevent further spread within Spain and across Europe.