The United World College in Mostar (UWCiM) was opened in 2006. The college is the core part of the UWC and International Baccalaureate (IB) Initiative in Bosnia and Herzegovina. UWC in Mostar is the first UWC with an explicit aim to contribute to the reconstruction of a post-conflict society and also the first to be housed within an existing public school.

The college is based within the Gymnasium Mostar, which teaches two national separate secondary school curricula, intended for Croat and Bosniak students as a consequence of the war in the 1990s. UWCiM students come from all ethnic groups in Bosnia and Herzegovina, as well as from the region and abroad. All students live, study and serve the community together creating a unique example of integrated education in post war Bosnia and Herzegovina.

UWC in Mostar aims to offer a convincing classroom model of integrated curriculum thus offering a model for broader educational reform in the county and the region. It educates students to learn and appreciate their differences, at the same time promoting equality, tolerance and critical thinking. The college also serves as the Centre for Professional Development of BiH Teachers who receive training in international educational standards.

UWCiM offers one curriculum, the International Baccalaureate Diploma Programme (IB DP) for students aged 16 to 19, and in their last two years of high-school. The IB DP is taught in over 2,000 schools in more than 120 countries across the globe, and is the most widely recognised high-school diploma in the world.

UWCiM students are selected purely on merit, by the UWC Selection Committee specific to their countries, and are awarded a full scholarship for their two-year studies. The scholarship covers the tuition and examination fees, textbooks, compulsory school trips, stationery, food, accommodation and health insurance.