Background: Paper presents the intentional use of biological agents for industrial, diagnostic and research purposes in enterprises in Poland. Material and Methods: The source of data is the National Register of Biological (in Polish KRCB) – the type of the database that gathers data about the intentional use of biological agents at work in Poland. The analysis includes tabular summaries of the data as of December 2017. Results: Notifications were sent by 598 enterprises for: diagnostic – 67.5%, research – 25% and industrial purposes – 75%. Those mostly were hospital diagnostic laboratories – 36%, entities other than hospitals – 32% and higher education and research units – 13%. In total, 4477 workers (91.3% women, 8.7% men) were exposed to biological agents. Agents from 2nd and 3rd group of risk were used in 581 and 106 enterprises, respectively. Escherichia coli bacteria was most frequently used (with the exception of non-pathogenic strains) in 504 enterprises (3529 exposed workers), Staphylococcus aureus – 495 enterprises (3464 workers) and Pseudomonas aeruginosa – 459 enterprises (3157 workers). In 58 enterprises, biological agents recognized by the International Agency for Research on Cancer as carcinogenic were used (viruses: hepatitis B virus (HBV) – 10 enterprises and 257 workers, hepatitis C virus (HCV) – 10 enterprises and 232 workers, Epstein-Barr virus (EBV) – 9 enterprises and 227 workers, human immunodeficiency virus type 1 (HIV-1) – 8 enterprises and 186 workers, human papilloma virus (HPV) – 3 enterprises and 94 workers, human herpes virus type 8 (HHV-8) – 3 enterprises and 22 workers, human T-lymphotropic virus type 1 (HTLV-1) – 1 enterprise and 17 workers; parasites: Schistosoma haematobium – 2 enterprises and 4 workers, Clonorchis viverrini – 1 enterprises and 2 workers, Clonorchis sinensis – 1 enterprises and 2 workers; bacteria: Helicobacter pylori – 10 enterprises and 137 workers). Conclusions: The network organization, legal base and central nature cause that the KRCB is a unique database that allows for diagnosis of the situation and tracking of dynamics in the context of occupational exposure to biological agents used intentionally in enterprises in Poland. Med Pr 2018;69(4):413–424