When AIDS was discovered, it was believed to be a "gay disease." This common misconception lasted until as late as the 1990's. This movie exceptionally exhibited peoples' reactions to AIDS and how ignorant they were about it during the time period of the film. Not much was known yet about AIDS because not enough medical research had been done, so naturally the public was misinformed. A perfect example of this ignorance comes in the scene when Andy is reading court cases in the library and he sneezes and people feel very uncomfortable. This discomfort comes from the fact that people thought at the time that AIDS could be contracted by any kind of contact with an infected person. The librarian comes over to Andy and says, "Sir we have a private research room open, would you like to use it?" to which Andy replies, "No, would you like me to use it?" In this scene specifically, the film exemplifies the attitude toward gays and people with AIDS in the 1980's.

Along with not knowing how AIDS was passed along, at that point in time, people thought that AIDS could only be contracted by gay people, hence the name "GRID," or Gay Related Immune Deficiency. This led to a growing dislike of gays and a lot of discrimination. The film also portrayed this aspect of 1980's society very well. Outside of the trial on the first day when Andy leaves the courthouse there are people outside protesting against gay rights with signs such as, "God made Adam and Eve, not Adam and Steve." There is also another example of peoples' emotions towards gays when in one scene Denzel Washington is inside a pharmacy and a gay man asks him to go out and have a drink with him because he likes that he is one of the few standing up for gay rights. Denzel responds with outrage and threatens to beat the man up. These scenes exemplify the discrimination gays went through in the 1980's.

Philadelphia is a film about the AIDS epidemic in the 1980's and its cause for discrimination towards gays and it portrays it just as it happened in history. Most people in the movie except close friends of Andy are hostile towards gays. Even the distinguished head of Andy's former law firm did not like gays. A smarter man like his character also shows how little people actually knew about AIDS at that time. A very educated man like the head of an enormous law firm does not know that AIDS was not only for gays and could not be passed through hugs, handshakes, or sneezes. Philadelphia excellently portrayed the social climate of the 1980's and peoples' lack of knowledge about HIV/AIDS.