In workplace sexual harassment cases, it is important that you document everything that has happened to make you feel uncomfortable based upon sex.  If the harassment takes place face-to-face, it is important to keep a detailed log outlining what happened and who was involved, along with the dates, times and locations of the incidents.  Save any written correspondence of a sexual nature, including emailed jokes and photos. It can also be important to get testimonials from anyone else who may have witnessed the harassing behavior.  When you report the incident to a supervisor, also be sure to keep copies of any materials you have submitted and document the interaction with your supervisor or human resources department. In many cases, the response of human resources or a supervisor can be insufficient to stop the sexual harassment, meaning that you will need this evidence going forward.