This study assesses the cost-effectiveness of May 2014 Supplementary Immunization Activity (SIA) for measles, in three districts of the province of Khyber Pakhtunkhwa, Pakistan. The costs and effects of providing two doses of measles vaccine through routine immunization have been compared to the costs and effects of providing it along with a supplementary campaign from provider’s perspective. The study findings indicate that SIA is a cost-effective strategy when measles incidence is high and vaccination coverage rates are low as in the cases of the three districts of Khyber Pakhtunkhwa covered in this study. The costs per DALY averted have been calculated as Rs. 5,791 (Abbottabad), Rs. 9,734 (Haripur) and Rs.7,198 (Mansehra). With a total of 15,803 DALYs averted in all three districts, measles supplementary immunization activity is considered a good public health investment for preventing childhood morbidity and mortality Supervisor: Dr. Durr-e -Nayab