We evaluated a trial-based approach to conducting functional analyses in classroom settings. Ten students referred for problem behavior were exposed to a series of assessment trials, which were interspersed among classroom activities throughout the day. Results of these trial-based functional analyses were compared to those of more traditional functional analyses. Outcomes of both assessments showed correspondence in 6 of the 10 cases and partial correspondence in a 7th case. Results of the standard functional analysis suggested reasons for obtained differences in 2 cases of noncorrespondence, which were verified when portions of the trial-based functional analyses were modified and repeated. These results indicate that a trial-based functional analysis may be a viable assessment method when resources needed to conduct a standard functional analysis are unavailable. Implications for classroom-based assessment methodologies and future directions for research are discussed. (Contains 2 figures and 2 tables.)