PurposePatients with hematologic malignancies (HM) receive palliative care (PC) less often and later than patients with solid tumors (ST). Patients’ lack of knowledge about PC and negative feelings about PC are barriers to their willingness to use PC. Is there a difference between patients with HM and ST in their knowledge and willingness to use PC?MethodsTwo hundred ten patients (85 HM, 125 ST) from an oncology day clinic at a university hospital participated in this cross-sectional, questionnaire-based survey.ResultsPatients with HM and ST had high knowledge and mainly positive feelings about PC. More than half of the patients answered that they would feel reassured by the use of PC, and one-third would feel anxious or hopeless. The majority of patients (58.3%) were willing to use PC. There are no significant differences between patients with HM and ST. In multiple regression analysis, perceived chance of cure and feelings of reassurance and anxiety are associated with willingness to use PC, but not with the HM/ST disease group. More than half (53.9%) of the participants would like the treating physician to choose the timing of a discussion about PC.ConclusionOur study shows a high level of knowledge and relatively positive feelings of patients about PC, with no differences between patients with HM or ST. They expect their treating physician to initiate communication about PC. Communication should include the patient’s feelings about PC and their chances of a cure.Supplementary InformationThe online version contains supplementary material available at 10.1007/s00520-023-07914-0.