Background: The Serious Illness Care Programme enables patients to receive care that is in accordance with their priorities. However, despite clarity about palliative care needs, many barriers to and difficulties in identifying patients for serious illness conversations remain. Aim: To explore healthcare professionals' perceptions about factors influencing the process of identifying patients for serious illness conversations. Design: Qualitative design. A thematic analysis of observations and semi-structured interviews was used. Setting/participants: Twelve observations at team meetings in which physicians and nurses discussed the process of identifying the patients for serious illness conversations were conducted at eight different clinics in two hospitals. Semi-structured interviews were conducted with three physicians and two nurses from five clinics. Results: Identifying the right patient and doing so at the right time were key to identifying patients for serious illness conversations. The continuity of relations and continuity over time could facilitate the identification process, while attitudes towards death and its relation to hope could hinder the process. Conclusions: The process of identifying patients for serious illness conversations is complex and may not be captured only by generic tools such as the surprise question. It is crucial to address existential and ethical obstacles that can hinder the identification of patients for serious illness conversations.