Visual Thinking Strategies (VTS) is an art-based education programme that originally aims to teach visual literacy, thinking, and communication skills through facilitated discussions of visual art. It has been introduced to healthcare programmes in higher education, such as medicine and nursing, but little has been reported for speech and language therapy (SLT) education. This study examined the effect of VTS as assessed by the quality of observations and linguistic structures used in written descriptions of an art image by SLT students. The pre- and post-VTS written samples of 82 final year SLT students collected over five different years were analysed. The written samples were generated by asking the students to view an art image and write down their observations in accordance with three prompting questions. Parameters related to observation skills and linguistic structures of written text were identified, coded, and counted. The results showed that there was a significant increase in the number of words used to discuss the image post-VTS, with a decrease in detailed observations but an increase in supported inferences noted. For the linguistic structures, there was a significant increase in the use of subordinate clauses and cohesive devices, indicating an increase in sentence complexity and cohesion of the narratives. The results suggest that VTS may stimulate more frequent use of linguistic features associated with critical thinking, reasoning and general observation skills in students.