Background: Brain metastases (BM) are common in patients with small cell lung cancer (SCLC). In recent years, the role of whole brain radiotherapy (WBRT) for brain metastases in lung cancer is being reevaluated, especially in the context of new systemic treatments available for SCLC. With this analysis, we investigate decision-making in SCLC patients with BM among European experts in medical oncology and radiation oncology. Methods: We analyzed decision-making from 13 medical oncologists (selected by IASLC) and 13 radiation oncologists (selected by ESTRO) specialized in SCLC. Management strategies of individual experts were converted into decision trees and analyzed for consensus. Results and conclusion: In asymptomatic patients, chemotherapy alone is the most commonly recommended first line treatment. In asymptomatic patients with limited volume of brain metastases, a higher preference for chemotherapy without WBRT among medical oncologists compared to radiation oncologists was observed. For symptomatic patients, WBRT followed by chemotherapy was recommended most commonly. For limited extent of BM in symptomatic patients, some experts chose stereotactic radiotherapy as an alternative to WBRT. Significant variation in clinical decision-making was observed among European SCLC experts for the first line treatment of patients with SCLC and BM.