Background: Standardized structured reporting (SSR) improves quality of diagnostic cancer reporting and interdisciplinary communication in multidisciplinary team (MDT) meetings, resulting in more adequate treatment decisions and better health outcomes. However, use of SSR varies widely among pathologists, but might be encouraged by MDT members (MDTMs). Our objectives were to identify barriers and facilitators (influencing factors) for SSR implementation in oncologic pathology from the perspective of MDTMs and their determinants. Methods: In a multimethod design, we identified influencing factors for SSR implementation related to MDT meetings, using 5 domains: (1) innovation factors, (2) individual professional factors, (3) social setting factors, (4) organizational factors, and (5) political and legal factors. Four focus groups with MDTMs in urologic, gynecologic, and gastroenterologic oncology were conducted. We used an eSurvey among MDTMs to quantify the qualitative findings and to analyze determinants affecting these influencing factors. Results: Twenty-three MDTMs practicing in 9 oncology-related disciplines participated in the focus groups and yielded 28 barriers and 28 facilitators in all domains. The eSurvey yielded 211 responses. Main barriers related to lack of readability of SSR: difficulties with capturing nuances (66%) and formulation of the conclusion (43%); lack of transparency in the development (50%) and feedback processes of SSR templates (38%); and lack of information exchange about SSR between pathologists and other MDTMs (45%). Main facilitators were encouragement of pathologists’ SSR use by MDTMs (90%) and expanding the recommendation of SSR use in national guidelines (80%). Oncology-related medical discipline and MDT type were the most relevant determinants for SSR implementation barriers. Conclusions: Although SSR makes diagnostic reports more complete, this study shows important barriers in implementing SSR in oncologic pathology. The next step is to use these factors for developing and testing implementation tools to improve SSR implementation.