Control of syphilis is a key component of Peru’s national strategy and activities to control human immunodeficiency virus (HIV) and sexually transmitted infections (STIs). Compared to other countries in the Region of the Americas, Peru has a relatively low prevalence of syphilis in pregnant women, and this fell from 2012 to 2016 – whereas the prevalence in the Region increased. Syphilis Interventions Towards Transmission (SITE) is a new tool developed by Avenir Health with support from the Pan American Health Organization. SITE simulates adult syphilis transmission in a country and can be used to look at the impact and cost-effectiveness of different STI control programs and interventions, guiding countries toward syphilis elimination targets. The model has been piloted in Peru to identify opportunities for optimizing the country’s STI and syphilis control strategy, plan, targets, and cost estimates. This report presents a compilation of syphilis epidemiological and programmatic data, the model calibration based on those, and projection results for several program scenarios suggested as relevant by the national HIV/STI program. It discusses results in terms of the health and transmission impact, service levels, and cost of alternative and combined packages of prevention, screening, and treatment interventions.