Little is known about the language trajectories of minimally verbal school-aged children with autism spectrum disorders. The present investigation conducted observations across two elementary schools over an entire school year to analyze the vocal language development of nine minimally verbal children with autism spectrum disorder between the ages of 6 and 10 years, and their educational service providers. A Language Environment Analysis™ device automatically recorded and disaggregated over 743 h of data on child vocalizations, and vocal interactions with adults. Vocalizations did not increase for eight of the nine participants, and conversational counts between participants and adults were near zero across the entire year. These results speak to the need for additional research examining language development and potential intervention strategies among minimally verbal children with autism spectrum disorder.