In the present study, caregivers were trained as therapists to conduct functional analyses (FAs) after staff-conducted FAs were inconclusive with 52 participants. Caregiver-conducted FAs identified at least 1 function for problem behavior when staff-conducted FAs were undifferentiated. When results of the staff-conducted FAs were questionable, subsequent caregiver-conducted FAs resulted in an exact match with staff-conducted FA in about 68% of cases but identified new functions in about 30% of cases. Function-based treatments based on caregiver-conducted FAs were effective in reducing problem behavior by an average of 96% relative to baseline. Results suggest that when staff-conducted FA outcomes yield inconclusive findings, using caregivers to conduct FAs is likely to produce differentiated results and ultimately result in the development of effective treatments.