INTRODUCTION: Developing a tool for measuring patient's needs is a vital step in 
the process of cancer treatment and research. In recent years, the European 
Organization for Research and Treatment of Cancer (EORTC) made a questionnaire 
to measure cancer patients' received information. Since validity and reliability 
of any instrument should be evaluated in the new environment and culture, the 
aim of this study was to assess the validity and reliability of the EORTC 
QLQ-INFO25 in Iranian cancer patients.
MATERIALS AND METHODS: One hundred seventy-three patients with different stages 
of cancer filled questionnaire EORTC QLQ-INFO25, EORTC QLQ-C30, and EORTC 
IN-PATSAT32. Twenty-five patients answered the questionnaire twice at an 
interval of 2 weeks. Reliability and validity of the questionnaire was measured 
by Cronbach's alpha, interclass correlation, test retest, inter-rater agreement 
(IRA), and exploratory factorial analyses.
RESULTS: Using a conservative approach, the IRA for the overall relevancy and 
clarity of the tool was 87/86% and 83.33%, respectively. Overall appropriateness 
and clarity were 94.13 and 91.87%, respectively. Overall integrity of the 
instrument was determined to be 85%. Cronbach's alpha coefficients for all 
domains and total inventory were top 70 and 90%, respectively. Interclass 
correlation index ranges between 0.708 and 0.965. Exploratory factorial analyses 
demonstrate six fields suitable for instrument. Correlation between areas of the 
questionnaires EORTC QLQ-INFO25 and EORTC in-Patsat32 represents the convergent 
validity of the questionnaire. Also, results show a standard divergent validity 
in all domains of the questionnaire (Rho <0.3). Low correlation between the 
areas of the questionnaires EORTC QLQ-INFO25 and EORTC QLQ-C30 (<0.3) 
demonstrates the divergence validity of the questionnaire.
CONCLUSION: The results showed that Persian version of the questionnaire EORTC 
QLQ-INFO25 is a reliable and valid instrument for measuring the perception of 
information in cancer patients.