The quality of information that oncological patients receive from health care professionals is an underestimated issue in Poland and Eastern European countries. There is lack of sufficient data on this subject. The European Organization for Research and Treatment of Cancer (EORTC) supplies a new tool for measuring the quality of information provided to cancer patients. The purpose of the study is the translation into Polish, pilot testing and preliminary validation of the EORTC information module (INFO25). Following the EORTC translation procedures, forward and back translations of the questionnaire were performed (English → Polish, Polish → English). The intermediate version of the INFO25 was pilot-tested together with the general questionnaire of quality of life (EORTC QLQ-C30). Reliability, validity and known-group comparison tests were performed. A total of 21 patients with different cancer diagnoses were recruited into the study (7 women and 14 men; mean age of 60,2 years, age range 25–73 years). Apart from filling out the INFO25, patients were interviewed about the difficulties with answering every questionnaire item. Patients' comments were analyzed and minor language changes were made to the initial translation. The internal consistency of the INFO25 showed a reliability of 0,78. The final version of the Polish translation of the INFO25 module was obtained and approved by the EORTC Quality of Life Department. It can now be used in clinical setting and for scientific purposes.