Deaf people often experience difficulty in understanding medication information provided by pharmacists due to communication barriers. We held medication education lectures for deaf and hard of hearing (HH) individuals and examined the extent to which deaf participants understood medication-related information as well as their attitude about medication. We used two questionnaires to compare the results from the deaf participants with those from the HH and hearing participants. We found that before the lecture, the deaf participants' understanding of medication use was lower than that of the HH and hearing participants. The deaf participants' knowledge increased after the lecture, but did not improve to the level exhibited by the HH participants. However, the deaf participants felt confident using medication despite their low comprehension levels. In conclusion, adjusting the medication information provided by pharmacists according to the recipient's reading level could help improve deaf patients' knowledge; however, such measures might not increase deaf patients' comprehension levels sufficiently.