Objective To mine the risk signals of ipilimumab-related adverse events (AEs) and provide reference for the safe use in clinical practice. Methods AE reports with ipilimumab as the primary suspect drug were collected from US FDA Adverse Event Reporting System database during March 1, 2011 to September 30, 2022. AEs were standardized and classified according to the preferred term (PT) and system organ class (SOC) in Medical Dictionary for Regulatory Activites version 26.0. The AE risk signals of ipilimumab were mined using reporting odds ratio (ROR) method. An AE with reports≥3, ROR≥2, 95% confidence interval (CI) lower limit of ROR>1 was defined as a risk signal. Risk signals were analyzed using descriptive method. Results A total of 12-329 AE reports were entered in the analysis, involving 1-915 PTs. Two hundred and sixty-eight risk signals (PTs) were obtained using ROR method, involving 21 SOCs. The top 10 PTs in report number were diarrhea, colitis, rash, fever, hypophysitis, adrenal insufficiency, decreased appetite, hypothyroidism, liver disease, and dehydration， all of which were common AEs in the labels. The top 10 PTs in signal intensity were hypophysitis, lymphocytic hypophysitis, immune-mediated dermatitis, immune-mediated adrenal insufficiency, hypopituitarism, immune-mediated liver disease, adrenocorticotropic hormone deficiency, immune-mediated encephalitis, autoimmune colitis, and immune-mediated hyperthyroidism. The SOCs involved were endocrine system diseases, skin and subcutaneous tissue diseases, hepatobiliary system diseases, gastrointestinal system diseases, and nervous system diseases. A total of 36 PTs were not included in the labels, and the top 5 in signal intensity were intracranial tumor hemorrhage, radiation necrosis, malignant pleural effusion, pulmonary granuloma, and lichenoid keratosis. Conclusions The main AEs of ipilimumab are diarrhea, colitis, rash, etc. In addition, ipilimumab might cause adverse reactions such as intracranial tumor hemorrhage, radiation necrosis, and malignant pleural effusion that are not recorded in label, which should be vigilant in clinical practice.