Little is known about the information parents of children with cancer find when searching for clinical trials information on YouTube. Thus, this study aimed to analyse the content, quality and reliability of YouTube videos focused on clinical trials for paediatric cancer. A descriptive cross-sectional design was used, and YouTube was searched using the phrases ‘clinical trials for children with cancer’ and ‘paediatric cancer clinical trials’. Videos that met inclusion criteria were assessed using the instruments Global Quality Scale and DISCERN. About half of the examined videos were in the GQS excellent-quality group and exhibited a total of 84,804 views. The mean time for videos was 5.7 minutes, they originated from the US or UK, were uploaded after 2016, and had a cancer centre/foundation or children hospital as video source. Half of them were focusing on early experimental trials and had a positive tone. Twenty percent were classified as useful without serious shortcomings, almost 50% as misleading with serious shortcomings, and 30% as inappropriate sources of information. In conclusion, most YouTube videos on paediatric cancer trials are not very informative and fall short of what could ethically be required regarding their facilitation of informed decision-making.