Objective Client satisfaction with mental health services is used commonly as an indicator of the quality of care, but there is minimal research on the construct of client satisfaction in youth services, and the extent to which satisfaction is related to improvements in clinical functioning versus other determinants. We examined the relationship between parent and youth satisfaction with youth services, and tested for significant determinants of satisfaction across three major domains: (1) change in youth clinical functioning; (2) youth/family service entry characteristics; (3) treatment/therapist characteristics. Method The participants were 143 youths receiving community-based outpatient care. Youths and parents were interviewed at service entry and six months later using well-established measures of clinical functioning and service satisfaction. Results Youths and parents reported generally high satisfaction, but the correlation between them was low. Despite testing for many potential predictors of satisfaction, very few significant effects were found. In regression analyses of significant predictors of satisfaction, higher youth satisfaction was significantly associated with Caucasian ethnicity and more positive youth expectations about treatment. Higher parent satisfaction was associated with lower caregiver strain at service entry, increased number of sessions, and improvement in youth-reported functional impairment. Conclusions Client satisfaction remains a rather elusive construct, but it is not necessarily a strong indicator of service effectiveness.