Summary
In Hungary a large increase in injecting new psychoactive substances (NPS) coincided with decreasing harm reduction efforts and rising HCV infection. NPS injectors in Hungary are at severe risk of blood-borne infections due to high levels of injecting and sexual risk behaviours within a high-risk environment. Stronger investment in evidence-based prevention measures, with special focus on young and new injectors, and expansion of hepatitis C treatment are urgently needed.