To achieve the simple goal of cadaveric body donation (CBD) program--gaining deceased donors--numerous scientific studies have been conducted, including the current study. This cross-sectional descriptive study used questionnaires to assess the motivational factors, attitudes, and knowledge of registered body donor participants toward CBD. Among 372 respondents, most (80.6%) were motivated by specific reasons such as "to save lives through medical education," "to contribute to medical research," and "to help medical students." Most respondents had good attitudes (61.7%) but poor knowledge (55.9%) about the CBD program, and there was no association among them (p = 0.08). However, the good knowledge and good attitude level were found 1.7 times (p = 0.02) and 2.4 times (p = 0.005) more, respectively, in basic-educated respondents than in highly educated respondents, implying the influence of peer conversation and message diffusion instead of knowledge or attitudes acquired through education. Additionally, 75% of respondents had co-registration within their family, peers were chosen by 66.7% of respondents as a source of information, and married respondents had 1.8 times better knowledge than unmarried respondents (p = 0.01), indicating the possibility of peer influence and growing peer communication. This study explored the poor knowledge status of registered donors, who are the cornerstone of knowledge propagation in the general population. Hence, after implementing this study, a knowledge-raising campaign for registered donors was conducted by distributing pamphlets about the CBD program, explaining keystone information, and supplementing a follow-up study. Moreover, this study will help us plan further strategies for program enhancement.