Disciplinary proceedings in the Police is a crucial issue given the size of this formation. For this reason, the number of relevant proceedings is also adequate. I will begin this discussion with a presentation of selected issues of disciplinary proceedings in the Police that shed light on this subject matter. The core interest of this study is evidentiary proceedings carried out as part of disciplinary proceedings, and to be more precise, the possibility of taking evidence from an expert witness’s opinion. This issue is largely regulated under the Code of Criminal Procedure. Naturally, there are some problems, e.g. when we talk about the system of verification of expert witnesses’ competences, but this is not subject of the discussion here. The legislator, in the act that regulates the procedure in a disciplinary offence committed by a police officer, did not include a regulation concerning an expert witness and did not refer to the application of another relevant provision either. This is why we are left with a question of what to do if special information must be obtained in the case. Another element of the discussion, after answering the first question, addresses the possibility of suspending the disciplinary proceedings if an opinion of an expert witness is being awaited. Moreover, I also include comments on the possibility of asking the opinion of an expert witness specializing in Polish law. The discussion carried out in this study is only an outline of problems that appear in the practice of conducting disciplinary proceedings.