Tumour necrosis factor (TNF)-α inhibitors are highly used in Romania for the treatment of autoimmune disorders, such as rheumatoid arthritis (RA), psoriasis, inflammatory bowel diseases, and ankylosing spondylitis. Biological therapy using TNF-α inhibitors is very effective but is associated with an increased risk of opportunistic infections, including active tuberculosis. Here, two cases are presented of patients with RA and psoriasis under biological therapy who developed very aggressive forms of disseminated tuberculosis, with a rapid progression to death. The authors conclude that patients undergoing biological therapy require thorough evaluation prior to initiating treatment, followed by continuous and rigorous monitoring by a multidisciplinary team during biological treatment, particularly in countries with a high incidence of tuberculosis.