The Voivodeship Administrative court in its judgment of 28 April 2010 case file VI SA/Wa 327/10 held that the Polish Patent Office should provide translation into Polish of documents that were allowed as evidence in administrative proceedings. Such conclusions stem from the Act of 7 October 1999 on the Polish language published in Journal of Laws (Dziennik Ustaw) of 1999 No 90 item 999. The authority/body provides official actions of public administration in the Polish language. The aforementioned act obliges the authority to make foreign language translation of the document. The examination of the contents of the document should be conducted in Polish, the one and only official language of the Polish administrative proceedings. Only then one can say that the procedural step, which consists of taking evidence from a document written in a foreign language, has been carried out correctly. The constitutional principle, which is reflected in rules of the Act on the Polish language, provides that the official language of the Republic of Poland is Polish and it requires that the documents being major evidence that affects the outcome of the administrative case, has been translated into Polish. Only then will it be possible to assess the accuracy of the examination of the content of such document.