Effective treatment of challenging behaviors in young children with autism spectrum disorder requires identifying consequences that maintain the behavior under specific environmental circumstances. Assessment strategies help to identify environmental factors setting the occasion for the behaviors to continue to occur. Many studies have used antecedent-behavior-consequence (ABC) data collection strategies, but few have examined its ability to effectively identify the function. Research supports the use of the trial-based functional analysis (TBFA) but few studies examine its effectiveness in the home setting. The current study attempted to answer which assessments might work best in the home setting. Treatment was implemented for each participant based on the results of their assessments. All assessments identified the function of behavior as verified by function-based treatments, but the ABC assessment identified additional functions for three of the participants while the TBFA was more precise. Implications and limitations are reviewed, along with future directions for behavioral assessment in the home.