The study's goals were: (a) to examine the influence of postsecondary education (PSE) in the form of academic enrichment courses on the cognitive performance of adults with intellectual disability (ID); (b) to examine their attitudes toward the program. The sample included adults who participate in PSE (N = 21; CA = 26-59) and a control group of adults who participate in leisure activities, but not in PSE (N = 28; CA = 25.5-59). The Participation in Cognitively-stimulating Activities Questionnaire (Lifshitz-Vahav et al., 2016) was used. The participants rated their participation in cognitively-stimulating activities during the week. These were grouped into five main activities: table games, watching TV, reading, using technological devices, participating in PSE. A crystallized and fluid tests battery was administered. Semi-structured interviews were conducted to examine the participants' feelings toward the PSE program. Mixed regression with chronological age, etiology, and participation in the five main activities as independent variables indicated that participation in PSE contributed to semantic fluency, homophones and Raven matrices scores. Path analysis suggested that the five main activities predict performance on the crystallized and fluid tests. The opposite model was insufficient. The findings support the compensation age theory and the cognitive activity theory for populations with ID. Theories of motivation (Maslow, 2012; Ryan & Deci, 2020) can serve as explanations for the participants' attitudes toward the program.