The peculiar characteristics of the Italian neoplastic patients, as far as their knowledge concerning the disease (information, prognosis, therapeutic options, etc) and the different cultural, environmental and health realities, place different problems on the routine application of the quality of life questionnaires which were constructed and edited in North European or North American Countries, even if correctly translated and validated in Italy. The QVonc (Quality of Life in Oncology) Project started five years ago from the common interest of medical oncologists who felt the need to make a careful study on some aspects regarding the evaluation of Italian patient's quality of life. A multidisciplinary working group, comprehensive of statisticians, epidemiologists, psychologists, nurses and methodologists, was then put together. During the last three years the Group produced a deep analysis of the different aspects and determinants of the italian patient's quality of life, mainly about their disease and medical environment perception. A prospective research was started in 1995 with the aims of identifying the contents of quality of life, using a sample of cancer patients as "experts" and of measuring the relevance of selected contents in different subgroups of patients. In the first study the quality of life dimensions were analysed as perceived from 248 neoplastic patients, uniformely and randomly distributed for pathology and place of residence in Italy, through an open questionnaire and interviews conducted by our psychologists. Some peculiar aspects of the quality of life perception in italian patients were evidenced: relationship with the family, with the medical team and health facilities, economic problems and occupational difficulties. The study confirmed that the information on the contents of quality of life can be derived only studying people suffering the specific disease and cast a doubt on the available QL instruments currently used. The second study evaluated the quality of life perception in 6939 consecutive cancer patients referred in the second week of July 1996 to 79 Italian medical oncology/radiotherapy institutions. Patients were asked to fill out a questionnaire concerning the importance of 46 domains of QL, each one scored on 4 levels (not at all, a little, much and very much). Domains were derived from a previous content analysis of 268 pts answers to 4 questions related to their own QL: "in your experience, what is QL?", "what is a bad QL?", "what is a good QL?", "Did the diagnosis and treatment received modify your QL?". 6939 patients entered the study; of these, 820 (11.8%) did not fill out the questionnaire due to various reasons. Among the 6,119 evaluable pts, the most frequent cancers were: breast (2,328), colo-rectal (968), lung (517), lymphoma (351), gastric (225). The most frequently chosen domains (much or very much) were related to health facilities or communication between patient-physician/nurse. Family relationship and general well being were also found important, while from the negative perspective the presence of the disease and the related anxiety were the most relevant problems. In conclusion, when choosing or constructing QL instruments, at least for Italian cancer pts, factors such as health facilities and pt--physician/nurse relationship should be more adequately considered. Most currently used QL questionnaires are probably lacking in this regard.