OBJECTIVES: Every year in Germany more than 25,000 men are diagnosed with prostate cancer. Theoretically all these patients are faced with a choice of treatment options: radical prostatectomy or radio therapy. Although this different treatments may have no differences in terms of survival, they may have very different consequences on the subsequent quality of life (QoL). Prerequisite to answer these questions is a reliable and valid instrument to assess these differences. Since in Europe the EORTC QLQ-C30 became the standard instrument to evaluate QoL in cancer patients, the task was to develop a disease specific module in addition to the core questionnaire to assess not just general QoL but as well prostate specific symptoms. METHODS: Between 1996 and 2000 different groups conducted historical cohort studies using the EORTC QLQ-C30 and a prostate specific module developed by Kuechler et al. The Reference Center Quality of Life in Germany put together these studies for an empirical meta-analysis. The main objective was to analyze the module’s psychometric properties. The total sample consisted of 1185 patients, of which 950 completed the QoL questionnaires. These 950 questionnaires were included in a detailed psychometric analysis. RESULTS: First step of this psychometric analysis was a principal component analysis, which revealed the scales: urinary problems, incontinence, erectile dysfunction, sexual problems, problems with partner, pain, heat, nutrition, and psychic strain. Their reliabilities indicated good to sufficient internal consistency with a Cronbach’s alpha (.70 to .89 except to two scales). The module showed good concurrent validity (correlations with “Global Health” from the EORTC QLQ-C30) and very good construct validity, since the module is able to discriminate between different treatment regimes, tumour stages and age. CONCLUSIONS: The prostate specific module is a reliable, valid and applicable measure for quality of life in patients with prostate cancer.