BACKGROUND: Lack of knowledge and awareness of oral cancer seem to be the main causes of diagnostic delay. Online resources are often used by patients to obtain health/medical information. However, there are no reports on the quality and usefulness of oral cancer audio-visual resources in Spanish. The aims of this investigation were to disclose the type of information about oral cancer available, and whether it may be useful to shorten the patients' oral cancer appraisal time-interval. MATERIAL AND METHODS: Cross-sectional study undertaken at three video-sharing sites on October, 13th 2019. KEYWORDS: "Cáncer oral"; "cáncer de boca". The first 100 results in each viewing list were retrieved by three reviewers. Demographical data was recorded, and interaction indexes, viewing rates, comprehensiveness, and usefulness were calculated for each video. The presence of non-scientifically supported information was also assessed. A descriptive analysis was undertaken, and relationships between variables were explored using the Spearman correlation test. RESULTS: A total of 127 videos were selected. They were produced mainly by mass-media (46.5%; n=59) and their length ranged from 0.28 to 105.38 minutes (median 4.15 minutes; IQR: 2.34-9.67). The most viewed video (10,599,765 views; visualization rate 726,508.9) scored 0 both in usefulness and comprehensiveness. The most useful video gathered 44,119 views (visualization rate 2.033.13). A highly significant positive correlation (0.643; p<0.001) could be observed between usefulness and comprehensiveness of the videos, together with negative correlations between the visualization rate and usefulness (-0.186; p<0.05), and visualization rate and comprehensiveness (-0.183; p<0.05). CONCLUSIONS: Online audio-visual material about oral cancer in Spanish is incomplete, of limited usefulness, and often includes non-scientifically supported information. Most of these resources are produced by mass media and healthcare professionals, with minor contributions from educational and healthcare institutions. Visualization rates negatively correlated with the usefulness and comprehensiveness of the contents in these digital objects.