BACKGROUND: The enhanced application of imaging techniques is resulting in the diagnosis of more patients with asymptomatic metastatic esophagogastric cancer (mEGC). We conducted a Delphi study to gather insights from European experts on the optimal timing for initiating palliative systemic therapy for these patients. METHODS: An online survey featured 14 scenarios where physicians chose their preferred timing for initiating systemic therapy: immediate(<3 weeks) or deferred. The standard scenario was a 65-year-old male, WHO/ECOG 0 with asymptomatic mEGC, 2 metastases in each lung, HER2 -, PDL1-CPS 2. In every subsequent case, one characteristic was modified. To investigate the fortitude of the physicians' preference for an immediate start, scenarios also included a patient who was motivated to start but preferred to defer if the physician deemed it judicious. Consensus was defined as ≥ 75 % agreement; scenarios without consensus were re-evaluated in Delphi round 2. RESULTS: Thirty-nine physicians participated in the first round, and 33 in the second round. Consensus to start treatment immediately was reached in 12 (86 %) scenarios. When patients preferred to defer, the consensus was to still advise to start palliative systemic treatment immediately in half (n = 7) of the scenarios. Only 2 scenarios (pre-existent WHO/ECOG 2 or 78 years old) reached the consensus that treatment could be deferred. CONCLUSIONS: In asymptomatic mEGC, immediate start of treatment is preferred by European experts. Consensus was established that treatment can be deferred for patients who prefer deferral and either have a pre-existent WHO/ECOG performance status of 2 or are of advanced age.