The objective of this study was to assess the long-term safety and tolerability of biologicals in a clinical setting. Data on adverse events (AEs) have been collected over a 5-year period by means of detailed reports sent in to the National Register of Biological Treatment in Finland (ROB-FIN) and validated by information collected by the National Agency for Medicines. Three hundred and eight reports on AEs were filed, concerning a total of 248 patients; this corresponds to 17% of all patients in the ROB-FIN register who started biological treatments. Skin reactions and infections comprised 35 and 28% of the AEs, respectively. Some cases of tuberculosis and other infections, heart failure and demyelinating conditions were seen. Our work demonstrates no unexpected AEs in a Finnish patient cohort consisting of rheumatoid arthritis and spondylarthropathy patients, although many of them were treated with combination treatments in common use in Finland. Biological treatment appears safe in the hands of the Finnish rheumatologists.