ObjectivesThe aim of this study was to analyze the efficacy and safety of percutaneous balloon pericardiotomy (PBP) in oncological patients who present with a malignant pericardial effusion (MPE).BackgroundThe use of PBP as a treatment for MPE is not standardized due to the limited evidence. Furthermore, the performance of a second PBP for a recurrence after a first procedure is controversial.MethodsThe BALTO Registry (BALloon pericardioTomy in Oncological patients) is a prospective, single‐center, observational registry that includes consecutive PBP performed for MPE from October 2007 to February 2022. Clinical and procedural, characteristics, as well as clinical outcome were analyzed.ResultsSeventy‐six PBP were performed in 61 patients (65% female). Mean age was of 66.4 ± 11.2 years. In 15 cases, a second PBP procedure was performed due to recurrence despite the first PBP. The procedure could be performed effectively in all cases with only two serious complications. Ninety‐five percent of cases were discharged alive from the hospital. During a median follow‐up of 6.3 months (interquartile range [IQR], 0.9–10.8), MPE recurred in 24.5% cases although no recurrences were reported after the second procedure. No evidence of malignant pleural effusion developed on follow‐up. The median overall survival time was 5.8 months (IQR, 0.8–10.2) and the time to recurrence after the first PBP was 2.4 months (IQR, 0.7–4.5).ConclusionsPBP is a safe and effective treatment for MPE. It could be considered an acceptable therapy in most MPE, even in those who recur after a first procedure.