Unresolved issues of ethical, methodological, and legal concerns in the use of normal healthy volunteers persist. Financial incentives in their recruitment offer a unique ethical dilemma because of questions surrounding payment. A review of literature was conducted to obtain research systematically examining volunteer motivation and the role of financial incentives. The primary selection criterion was motivation and payment to volunteers; seven studies met the criterion for re view. Studies that have systematically investigated volunteer motivation have found financial rewards to be an important motivator among normal healthy volunteers in their decision to participate in clinical trials. Also evident is that differences based on demographic characteristics exist in the motivation and rates of volunteerism. Ethical issues surrounding the use of normal healthy volunteers are discussed, with attention to the issue of financial incentives (e.g., economically vulnerable volunteers, undue inducements). Regulations, guidelines, and recommendations are discussed with regard to volunteers and financial incentives.