Online anatomical images are an effective resource to improve knowledge acquisition and practical exam performance in gross anatomy.

Anatomical knowledge is fundamental to the training of students enrolled in health sciences degree programs. Although the use of images is common in anatomy teaching, it remains unclear whether progressive autonomous exposure to cadaveric images improves student performance in assessments based on cadaveric material. The aim of this study was to evaluate the effectiveness of high-quality cadaveric images for teaching visceral anatomy to first-year medical students at the University of Valencia, focusing on their impact on cadaver-based practical performance. High-quality images of dissections from the head, neck, and thoracic regions were obtained and made available to students for self-directed study and self-assessment in preparation for the practical examination in the dissection room. A cross-sectional comparative study was conducted in which two theoretical groups of students had access to the images (n = 180), while two additional groups served as controls (n = 182). A second analysis was also performed within the intervention groups using online quizzes to evaluate knowledge acquisition, together with a survey assessing student satisfaction with the learning materials. Results showed a significant improvement in online quizzes and practical exam questions with images' aid, indicating enhanced knowledge acquisition. Furthermore, students with access to the images achieved significantly higher scores in the practical examination than those in the control groups. These findings suggest that structured digital resources that support independent learning can improve knowledge acquisition and performance in cadaver-based assessments. Such resources may be particularly valuable in contexts where access to cadaveric material or teaching time is limited.