Introduction: Emotional and behavioral problems are common in adolescents with mild to borderline intellectual disabilities (MBID). Basic Psychological Needs Theory connects fulfillment of basic psychological needs (autonomy, relatedness, competence) to ill-being (mental health problems). The associations between the frustration and satisfaction of basic psychological needs and indicators of mental health problems are the subject of this study. Method: Adolescents with MBID (N = 324, mean age 15.2 years), filled out questionnaires on basic psychological needs (BPNSFS-ID) and on anxiety (SCARED), depression (CDI) and aggression (Externalizing Problems scale of YSR). A subgroup of adolescents with MBID and severe behavioral problems (MBID-SBP) was compared to a general subgroup (MBID-G). Results: Outcomes for adolescents with MBID-SBP were worse than for adolescents with MBID-G on most measures. BPNSFS-ID frustration was positively associated with mental health problems. Correlations for the BPNSFS-ID satisfaction scales were positive but weaker. Associations within the MBID-SBP subgroup were stronger than for the MBID-G subgroup. Discussion: Frustration of BPN in particular is associated with mental health problems. Attending basic psychological needs may potentially help to counter ill-being.