OBJECTIVES: To evaluate the impact of acromegaly on health-related quality of life (HRQOL) in European patients treated with Sandostatin® LAR®. The secondary objectives were to investigate the correlation between HRQOL and subpopulations based on exploratory variables [sociodemographic and disease-specific markers, eg growth hormone (GH) and insulin-like growth factor (IGF-I)] and to compare the results of the 22-item [8 physical and 14 psychological] Acromegaly Quality-of-Life questionnaire [ACROQOL] and Short Form-36 Health Survey [SF-36] in this population. Some of data collected will support also the ongoing validation of ACROQOL questionnaire. METHODS: This is the largest European multinational, open, non-comparative, single evaluation, observational trial evaluating the HRQOL of patients with acromegaly treated with Sandostatin® LAR®. This preliminary analysis presents interim results from 208 Italian and 71 Spanish patients. Recruitment is ongoing in England, France, Germany, Greece, Portugal, and Turkey. A total of more than 500 patients is expected. GH and IGF-I levels were measured within two months of completion of the questionnaires and sociodemographic data were also recorded. Multivariate analyses were used to explore relationship between HRQOL score and clinical and sociodemographic variables. RESULTS: From this preliminary analysis, there was no apparent relationship between HRQOL and sociodemographic variables ; and no correlation with levels of GH or IGF-I. There was a marked correlation between ACROQOL and physical component score of SF-36, but less significant correlation between ACROQOL and mental component score. The overall impact of acromegaly on HRQOL in patients treated with Sandostatin® LAR® has not yet been analysed. CONCLUSIONS: ACROQOL may be a more descriptive measure of HRQOL in the acromegaly population than the SF-36. In terms of the SF-36, there was a superior correlation between the physical function component and ACROQOL than with the mental component score, suggesting that the ACROQOL is more sensitive to the psychological impact of the disease.