The preliminary study was performed to determine the frequency of tuberculin skin test (TST) positivity among 26 patients and their donors screened by TST to investigate whether tuberculin positivity of a recipient or donor influenced the rate of tuberculosis disease, transplant-related events, and to evaluate the effectiveness of isoniazide (INAH) prophylaxis administered to those with positive TST. The frequency of TST positivity was 23% (n = 6) among recipients and also 23% (n = 6) among donors. Two recipients and five donors with positive TST received INAH prophylaxis for six months. Our use of INAH prophylaxis in transplant patients was very conservative because of the risk of drug interaction. The transplantation procedure was not postponed for either recipient or donor TST positivity. Despite the high frequency of tuberculosis in our country, we have not detected any case of tuberculosis in our center, either among the purified protein derivative-screened (n = 26) or non-screened (n = 128) patients except for disseminated tuberculosis infection because of BCG vaccination in two patients with severe combined immunodeficiency. In conclusion, TST positivity in either recipient or donor may not be a contraindication for bone marrow transplantation and the procedure may not be postponed. Pretransplantation TST screening may be needed in countries where tuberculosis is common in the general population.