OBJECTIVES: To evaluate cost-effectiveness of biologics used in patients with psoriasis in Colombia and Peru. METHODS: We estimated direct costs of etanercept, adalimumab, ustekinumab and infliximab based on their labels for first/induction year and second/maintenance year (EUR1=COL$2340=SOL$357). For etanercept we considered two induction schemes: 50mg weekly 52 weeks-D1- and 100mg 12 weeks followed by 50 mg 40 weeks-D2-. Effectiveness was evaluated as 75% reduction in Psoriasis Area and Severity Index-PASI 75- from meta-analysis presented by Hawkins et al. in the 14th International ISPOR: infliximab=80%; ustekinumab=69%; adalimumab=59%; etanerceptD2-=52%; etanerceptD1=39%. Infliximab and ustekinumab effectiveness were not significantly different. However, both were significantly superior to etanercept (D1 and D2). RESULTS: In Colombia, Ustekinumab was dominant (€29.012 in 2 years) generating cost savings of -€4.416 vs. etanerceptD1; -€7.411 vs. adalimumab; -€8.119 vs. etanerceptD2 and -€25,340 vs. infliximab; with higher or same effectiveness than the other biologics used in that country. In Peru, all the options were more effective and more costly than the standard of care (etanerceptD1). The ICER per patient with PASI 75 of etanerceptD2, adalimumab, ustekinumab and infliximab, compared to etanerceptD1 were €21.654; €19,860, €13,036 and €29,008, respectively. Then, the efficiency frontier was formed by etanerceptD1, ustekinumab and infliximab. Given evidence shows the last two products do not have effectiveness significant differences, ustekinumab became the dominant option. An additional analysis was done supposing that infliximab’s effectiveness was superior to ustekinumab’s. The ICER per patient with PASI 75 between these products was €220,352 in Colombia and €50,989 in Peru. These values were higher than Colombian and Peruvian health systems’ willingness to pay per PASI 75 (€40.334 and €29,242, respectively), calculated based on average effectiveness and costs of biologics. CONCLUSIONS: In the studied LA countries, Ustekinumab resulted the most cost-effective biologic, even being cost-saving in Colombia. These results corroborate those observed in European countries.