Recipients of SOT and HSCT constitute a risk group for becoming ill with tuberculosis (TB). The prevalence of active TB in patients undergoing TOS is higher than in patients undergoing HSCT, probably for the shortest period of immunosuppression of the latter. Most TB cases occur in transplant patients by reactivation of latent infection after immunosuppression, which occurs most often within the first year post-transplant, causing graft loss and in some cases death. Relevant variables to assess the risk of TB infection in a transplant recipient are the medical history of donor and recipient, images, microbiology and tuberculin tests and interferon gamma levels. PPD is routinely performed in the donor and in the recipient before transplantation. If PPD is > 5 mm in the recipient or > 10 mm in the donor, it is neccesary to exclude active TB (pulmonary and renal) (A2). It is recommended chemoprophylaxis in recipients PPD (+) and in recipients with recent seroconversion (B3), if the donor has a history of untreated TB, there was contact to someone with active TB (B3), the radiological imeges are suspect (A2) and interferon gamma release assays is (+) (B2). The selected drug is isoniazid (C3).