Maximizing participation in cancer research is important to improve the validity and generalizability of research findings. We conducted a four-arm randomized controlled trial to test the impact of a novel video invitation on participant response. We invited childhood cancer survivors and parents of survivors <16 years to complete questionnaires. We compared response rates to an invitation letter (control) vs receiving the letter plus a video invitation on a flash drive presented by a childhood cancer survivor, a pediatric oncologist or a researcher. We explored factors associated with viewing the video and examined the impact of enclosing the USB on study costs. Overall 54% (634/1176) of questionnaires were returned. Participants who received a video invitation on a USB were more likely to return the questionnaire than those who did not (58% vs 47%, P < .001). Participation rate did not significantly differ by video presenter. Forty-seven percent of participants who received a USB reported watching the video, of whom 48% reported that the video influenced their decision to participate. Participants with a lower income (OR = 0.43, 95% CI = 0.25-0.74, P = .002) were more likely to report watching the video. Participants who received a video invitation required significantly fewer reminder calls than those who only received a written invitation (mean = 1.6 vs 1.1 calls, P < .001), resulting in a 25% recruitment cost-saving for the study. Adding a USB with a video study invitation to recruitment packages is a cost-effective way of improving study participation. This is important in an era of declining study participation and underrepresentation of vulnerable populations in research.