The article is an attempt of providing basic information on the Polish Register of Ships – (rejestr okrętowy), its legal principles, construction and mode of operation. The text is by no means a comprehensive legal analysis of this institution – such a study would have necessitated much more time and effort, but it is rather a synthetic guidance on how the register is designed, how it works, or at least how it should have worked and what sort of purposes it primarily serves. The publication reflects a present status of legislation in Poland, i.e. the respective regulations of the Polish Maritime Code enacted in 2001. It should be noted that a draft of a new Polish Maritime Code has recently been prepared, that designs the Polish Register of Ships in a slightly different, more flexible and up-to-date, mode. However, at the moment, we are not able to predict when the new regulations might be enacted and become applicable. Polish maritime hypothecation and mortgage are subject to a separate study that shall be presented in the near future.