The purpose of this study was to examine the effectiveness of UDL training on general education teacher candidates' daily lesson plan writing skills. The participants were 97 teacher candidates in a general education programme. They were required to write a lesson plan before and after the three-hour UDL training. The single group pre-test--post-test design was conducted to see whether there was a change on the dependent variable. The results of this study indicated that there was a statistically significant difference between the total scores of the participants on two lesson plans from the pre-test to post-test. The UDL training was found to be successful at increasing lesson plan writing skills and creating more responsive learning environments for general education teacher candidates.