Understanding the effects of prostate cancer on quality of life of affected patients is essential for clinical research and also for optimal management and care.The main objective of this study was to evaluate the psychometric properties of a Moroccan dialect version of the quality of life questionnaire(EORTC QLQ-PR25).The study was conducted among patients with prostate cancer in oncology department of the Ibn Rochd University Hospital Mohammed VI Center for cancers treatment in Casablanca during the period of study(from January to December 2017).Statistical analysis data was done using R software.Internal consistency was tested using Cronbach’s alpha.A total of 82 subjects were included,the mean age of patients was 69.6 years with a standard deviation of 7.9 years.The majority of them were illiterate,with 59.8%,and urban people about 60%.Good reliability was revealed for the Moroccan dialect version with Cronbach’s alpha coefficient ranging from 0.17 for“sexual function”dimension to 0.83 for“urinary symptoms”dimension.Reproducibility of the scale was good with intra-class correlation coefficients ranging from 0.69 for“sexual function”dimension to 0.87 for“urinary symptoms”dimension.Scale reproducibility was good with intra-class correlation coefficients ranging from 0.69 for“sexual function”dimension to 0.87 for“urinary symptoms”dimension.Dialectal version obtained showed good reliability for the dimension“urinary symptoms”and acceptable for other dimensions except for“sexual function”which was not satisfactory.