This study observed expressive communication of 17 Australian and 15 Taiwanese children with autism who were mute or had limited spoken language during 2 hour regular school routines and analyzed teacher instructions associated with elicited expressive communication. Results indicated: (a) the frequency of occurrence of elicited expressive communication was very low; (b) the incidence of elicited expressive communication was negatively correlated with autism severity; (c) verbal prompt and a combination of verbal prompt and modeling were the most common types of teacher instruction and the use of physical prompt was a rate event; (d) modeling and verbal prompt were positively correlated with speech and unaided augmentative and alternative communication (AAC) and a combination of verbal prompt and modeling was positively associated with aided AAC; and (e) modeling, verbal prompt, and a combination of modeling and verbal prompt were positively correlated with requesting function and commenting function was positively correlated with modeling and verbal prompt.