The aim of this two years master thesis is to explore the relationship between public libraries and deaf adults. I want to know if deaf adults are a prioritized group in Swedish public libraries. Deaf adults use Swedish sign language witch is a visual language and differs from Swedish. I discuss the difference in Swedish Sign Language and Swedish and the importance of Sign Language literature. I also explore what methods can be used for mak-ing the library service towards the deaf group more customer centered and service oriented.The lack of sign language knowledge among the library personnel can lead to communication barriers. I want to illustrate these communication barriers, both psychological and semantic barriers, with Richard Dimble-by and Graeme Burton´s interpersonal communication theory. The psychological barriers consist of negative attitudes and prejudices. In this case these psychological barriers prevent the libraries from further proceedings with the marketing of their service, all based on the notion of deaf being uninterested in library service. This, on the other hand, leads to deaf people not knowing what public libraries can offer and therefor has become some-what of an invisible group in the libraries today.I performed ten surveys on ten public libraries in Sweden and a more detailed questioner to Teckenhörnan in Örebro public library. Thees surveys was done based on the IFLA Guidelines for Service for Deaf People. The result of this survey shows that deaf adults are not a prioritized group in public libraries. The lack of knowledge among library personnel about deafness, sign language and an understanding of the situation of deaf people is an obstacle. It is important to separate deaf from other disabled groups since deaf is more a linguistic minority then a disabled group.