This multi‑country study assessed recurrent costs of HPV vaccine delivery after introduction, focusing on financial and opportunity costs across health system levels. Conducted in Ethiopia, Guyana, Rwanda, Senegal, Sri Lanka, and Uganda, findings show school‑based vaccination is predominant, with mixed approaches in some contexts. Service volume strongly influenced cost efficiency, as sessions vaccinating more girls reduced cost per dose. Transitioning from two to one dose could lower expenses by up to 45% and reduce procurement costs, including syringes, by nearly 49%. These insights guide planning for sustainable, cost‑effective HPV vaccination strategies.