Although sustainable development is gaining increasing global attention, the actual level of knowledge about this topic among current experts and leaders remains limited. This issue is likely to persist among future leaders and experts unless higher education study programs incorporate sustainable content more effectively and accurately in the near future. The main objective of this paper is to examine the inclusion of sustainable content in accredited higher education study programs in Slovenia with the measure of the Sustainability Assessment Score (SAS) of individual study programs and to identify statistically significant differences in SAS between different groups of study programs based on factors such as the type of institution offering the program, the KLASIS-P16 classification, the study cycle of the program, and the presence of sustainability-related keywords in at least one course title within the program. Based on an analysis of all 956 Slovenian higher education study programs, the SAS was calculated for each program by searching for the occurrence of sustainability-related keywords in Slovenian, as identified by a focus group of renowned experts in sustainable development in Slovenia. These keywords included: sustainable development, green/environmental, environmental protection, circular economy, social responsibility, and ecology. Parametric tests (T-test and ANOVA) were applied to determine statistically significant differences in SAS across different groups of study programs. The results revealed that higher education study programs offered by private institutions and programs containing courses with sustainability-related keywords in their titles had higher SAS. Additionally, statistically significant differences in SAS were observed between study programs across different fields.