Film translation has become a worldwide field in which subtitlers translate and transfer language and style from one culture into another. Subtitling has always been affected by cultural elements. The purpose of this study was to find out how professional subtitlers differ from fansubbers when dealing with such expressions concerning the strategies that both groups use to subtitle these expressions. To achieve the goals of this study, the researchers identified 120 slang expressions from two American movies, Goodfellas and Training Day, but chose only 30 slang expressions to report on how they were rendered by both groups.  Results of the study showed that the professional subtitler and the fansubbers faced many challenges and used varying strategies when subtitling slang expressions. The challenges were related to the presence of some cultural terms and different types of slangs which are unfamiliar to most subtitlers. The most frequent strategies used by the professional subtitler and fansubbers were paraphrase, euphemism, omission, and calque. The study recommends that further studies be conducted on a larger sample of slang expressions in American or British movies and TV series. In addition, the subtitling of these slang expressions can be investigated in other target cultures and languages such as Spanish, Persian, Turkish, Greek, and Kurdish.