Objective: To present from the Danish Database for Biological Therapies in Rheumatology (DANBIO) the frequencies and types of adverse events as well as risk factors during treatment with biological agents in clinical practice.Methods: Adverse events during the first 2 years of clinical use of biological agents in Denmark were reported to the nationwide DANBIO and compared to the mandatory reports to the Danish Medicines Agency.Results: Almost 90% of the patients treated with biological agents were registered in the DANBIO, and the database picked up 20 times as many adverse events as the Danish Medicines Agency. Infections and hypersensitivity reactions were the most prevalent adverse events. Age, disease duration, and previous number of disease‐modifying anti‐rheumatic drugs (DMARDS) were found to be risk factors for bacterial infections.Conclusion: A routine‐based Danish database for biological therapies covers approximately 90% of patients and improves the reporting of adverse events.