Oncologists frequently have sickness certification (SC) consultations, however, little is known about their experiences of such tasks.ObjectiveTo investigate oncologists’ experiences of organisational prerequisites for SC tasks, and if lack of resources was related to experiencing SC as problematic.MethodQuestionnaire data from 342 oncologists in Sweden were used for descriptive statistics and to calculate odds ratios (OR) with 95% confidence intervals (CI).ResultsThe majority (92.2%) had SC consultations weekly; 17.8% of the oncologists experienced such consultations as problematic weekly. About a third appreciated the national guidelines for SC (34.5%) and had joint routines/policies regarding SC at their clinic (29.7%). Experiencing SC consultations as problematic was associated with stating not having enough resources for such work (OR 3.47; 95% CI 1.92–6.25). Lack of resources was associated with: experiencing lack of competence in insurance medicine (3.34; 1.92–5.82), conflicts with patients regarding SC (4.22; 1.96–9.07), finding it problematic to manage the two roles as medical expert and as the patient's treating physician (3.31; 2.04–5.34), or to assess work capacity (2.28; 1.46–3.56).ConclusionAlthough oncologists often had SC tasks, most did not experience them as problematic weekly. However, lack of resources for SC tasks was associated with experiencing SC as problematic.