Situational comedies, or sitcoms, have become one of the most famous sources of entertainment in the 21st century. Sitcoms have explored a number of ways to provide laughter and entertainment to their audience. With so many TV shows and movies created in the past, other TV shows and movies decided to achieve comedy by referencing shows from the past in a suitable way. Some shows also refer to past events, people who are famous or bear an importance in any way. One such show is The Big Bang Theory which focuses on referencing events, people, shows, and movies that are somewhat related to the group of people perceived as nerds or geeks. The show refers to things that are related to science in general and the science fiction (sci-fi or SF) genre. There are not a lot of people who are familiar with physics, astronomy, and chemistry in such depths, as well as not being a part of SF fandom. Due to that and the fact that this show is centered around these two things, it is important that people understand references in the show to comprehend the humor that the show is trying to achieve. This paper will try to further explain intertextuality and its origins in the theoretical part, as well as intertextual use (verbal, nonverbal, written, mimicked, and others) in this particular TV show.