Communication through sign language is essential for teachers of deaf students. This study sought to assess and evaluate the sign language proficiency of preservice teachers of deaf students to help preservice teacher preparation program designers identify what aspects of sign language need to be focused on and provide recommendations to improve preservice teachers' sign language levels. An exploratory research design was used through questionnaires distributed to a convenience sample. The research subjects were undergraduate female students (N = 36) enrolled in a Saudi Arabian university's preservice preparation program for teachers of deaf students. This study's results indicate that preservice teachers of deaf and hard of hearing students scored highly for lexical signs, on an average level for iconic lexical signs, but on a low level for the domain of arbitrary lexical signs. There was a significant effect of participants' grade point averages (GPAs) on their overall sign language proficiency score. No significant effect of age, academic level, and the number of completed sign language training on overall sign language proficiency score was reported. This study's outcomes show that preservice teachers' sign language level needs to be improved and developed. Recommendations are presented for future research and preservice teacher preparation program designers to develop learners' sign language skills.