HIV AIDS treatment is a lifelong treatment, so the continuity of treatment is very influential on the treatment outcome. Affordability is one aspect that can improve access and continuity to HIV AIDS and opportunistic infections (OI) treatment in Children Living with HIV AIDS (CLWHA). This study was conducted to determine the affordability of HIV and OI treatment costs on CLWHA in the study area. The study was conducted cross sectional in 5 provinces, 10 districts / cities and 238 CLWHA companions as a responden. This study showed that source of medical cost still varies between health insurance (BPJS), free local government and out of pocket cost, with median cost of treatment for once visit was starting from Rp. 52,773 to Rp. 222,042 with maximum cost was Rp. 1,203,000. The average percentage of treatment costs compared to household expenditures for 1 month were ranged from 3.8 to 8.9% with a maximum value of 56.7%. The most medical costs covered by CLWHA was a laboratory tested, while the non-medical costs that were still problems was transportation cost to health facilities. Based on this study, the government needs to facilitate the HIV AIDS treatment in the BPJS treatment package starting from enrollment, doctor's examination, ARV and OI medication, routine laboratory tested and OI treatment. Case manager or counselor should begin to be brought closer to the health facility closest to the patient's home, so CLWHA's companion does not feel worried about the stigma during treatment.