The importance of outpatient cancer care services is increasing due to the growing number of patients having or having had cancer. However, little is known about cooperation among physicians in outpatient settings. To understand what inter- and multidisciplinary care means in community settings, we conducted an amplified secondary analysis that combined qualitative interview data with 42 general practitioners (GPs), 21 oncologists and 21 urologists that mainly worked in medical practices in Germany. We compared their perspectives on cooperation relationships in cancer care. Our results indicate that all participants regarded cooperation as a prerequisite for good cancer care. Oncologists and urologists mainly reported cooperating for tumour-specific treatment tasks, while GPs’ reasoning for cooperation was more patient-centred. While oncologists and urologists reported experiencing reciprocal communication with other physicians, GPs had to gather the information they needed. GPs seldom reported engaging in formal cooperation structures, while for specialists, participation in formal spaces of cooperation, such as tumour boards, facilitated a more frequent and informal discussion of patients, for instance on the phone. Further research should focus on ways to foster GPs’ integration in cancer care and evaluate if this can be reached by incorporating GPs in formal cooperation structures such as tumour boards.