To assess what participants in company-sponsored clinical trials wish to know about financial aspects of the study. Cross-sectional questionnaire administered to 324 participants in six clinical trials conducted at the Royal Melbourne Hospital in 1999-2000 and 2006 for non-acute conditions (asthma, chronic obstructive pulmonary disease, osteoporosis, rheumatoid arthritis, diabetes and influenza vaccine efficacy). Participants' desire for information on study funding, investigators' conflicts of interest, and use of accrued funds. 259 participants (80%) completed the survey. Participants wanted to be informed about the identity of the project sponsor (148 participants; 57%), whether the investigators owned shares in the company (105; 41%) or received travel grants (83; 32%), how much funding was accrued at study completion (88; 34%), how accrued funds were used (98; 38%), and who approved their use (91; 35%). After adjusting for year of survey and level of education, younger subjects (aged