In Denmark, treatment of TB is generally recommended only if the diagnosis is confirmed bacteriologically. This policy may cause a delay in treatment if the patients are smear negative. The duration of the treatment delay, and whether the delay would cause any serious health problems for the individual or risk of contact infections, in a retrospective examination of 324 cases of pulmonary TB was investigated. The mean treatment delay was longer in the oldest age group. Concerning death due to delay, there was no risk for those patients who were not weakened by other disease or old age. Only 11 patients (3.6 percent) over the age 10 years were treated without bacteriological confirmation (1 percent for Danes). The infection risk from the smear- negative but culture-positive patients was minimal as only one subject was definitely infected from a smear-negative patient. However, a risk of transmission exists from patients who are initially culture-negative but later become smear-positive. In conclusion, the epidemiological and individual risks were sufficiently low to continue the rather restrictive treatment policy.