Globalization and lifestyle changes have led to health becoming a major social preoccupation of the population. Spas are no longer just centers for disease treatment, but a means of preventing diseases and protecting human health. An increasing number of young people are trying to improve their health through spa treatments. This is why there is a growing tourist offer of spa centers. Bosnia and Herzegovina (B&H) has rich natural resources that are conducive to the creation of spas. Therefore, this study looked into spa offers and evaluated the transformation of medical spas into modern spa centers in order to improve competitiveness. Spa transformation survey was conducted on the example of spas in B&H. Six, out of a total of fifteen registered spas in B&H, have been chosen randomly. The spa offer was evaluated by applying the decision-making model and expert decision-making. The obtained results showed that the spas of Ilidža - Gradačac and Ilidža - Sarajevo have "good" transformation; the spas Dvorovi and Mlječanica have "middle" transformation, while the spas of Gata and Sanska Ilidža have "bad" transformation in the process of creating modern spas. Based on the results of this study, spa managers can obtain the necessary information on how to adjust the offer to make those spas more competitive. In addition, the spas will also generate higher revenues. The decision-making model used has shown good results and can be applied to future studies and research.