BACKGROUND: Collection of genetic biospecimens as part of critical illness investigations is increasingly commonplace. Oversight bodies vary in restrictions imposed on genetic research, introducing inconsistencies in study design, potential for sampling bias, and the possibility of being overly prohibitive of this type ofresearch altogether. We undertook this study to better understand whether restrictions on genetic data collection beyond those governing research on cognitively intact subjects refl ect the concerns of surrogates for critically ill patients. METHODS: We analyzed survey data collected from 1,176 patients in nonurgent settings and 437 surrogates representing critically ill adults. Attitudes pertaining to genetic data (familiarity, perceptions, interest in participation, concerns) and demographic information were examined using univariate and multivariate techniques. RESULTS: We explored differences among respondents who were receptive (1,333) and nonreceptive (280) to genetic sample collection. Whereas factors positively associated with receptivity to research participation were "complete trust" in health-care providers (OR, 2.091; 95% CI, 1.544-2.833), upper income strata (OR, 2.319; 95% CI, 1.308-4.114), viewing genetic research "very positively" (OR, 3.524; 95% CI, 2.122-5.852), and expressing "no worry at all" regarding disclosure ofresults (OR, 2.505; 95% CI, 1.436-4.369), black race was negatively associated with research participation (OR, 0.410; 95% CI, 0.288-0.585). We could detect no difference in receptivity to genetic sample collection comparing ambulatory patients and surrogates (OR, 0.738; 95% CI, 0.511-1.066). CONCLUSIONS: Expressing trust in health-care providers and viewing genetic research favorably were associated with increased willingness for study enrollment, while concern regarding breach of confidentiality and black race had the opposite effect. Study setting had no bearing on willingness to participate.