Prior research has indicated that people with an intellectual disability experience higher levels of negative affect, including anxiety and fearfulness, than people who are not disabled. This is important because research has also suggested a negative relationship between emotional distress and adaptive behaviour, albeit in nondisabled populations. The present study investigates the relationships between fear, anxiety, and adaptive behaviour in children and adolescents with an intellectual disability as compared to youth of average intelligence. A sample ranging in age from 7 to 18 years participated in the study. Fifty-one respondents (30 male, 21 female) constituted the intellectually disabled sample, and 57 (28 male, 29 female) constituted the comparison group. Analysis revealed higher levels of fear and anxiety among the group with disabilities. An inverse relationship was also found between negative affect and adaptive behaviour among the youth with disabilities, but not for youth of average intelligence. The results are discussed in relation to their implications for intervention programs.