Bedaquiline (Bdq), a novel TB drug, is referred to the most effective drugs and used for the management of multidrug-resistant tuberculosis (MDR-TB). The drug produces a cardiotoxic effect, and its use is limited to six months. We describe a clinical observation of prolonged bedaquiline use in the treatment for MDR-TB using a restricted number of drugs, to which susceptibility was preserved, in a 12-year-old child. The previous treatment course had failed; the patient remained sputum-positive after eight months of the treatment. We used a personalized approach to chemotherapy correction based on repeat drug susceptibility testing. The treatment regimen only contained those drugs, to which susceptibility was preserved: amikacin, cycloserine, linezolid, bedaquiline (AmCsLzdBdq). Amikacin was withdrawn after three months due to the development of sensorineural hearing loss. The treatment was continued with CsLzdBdq. The total chemotherapy course took 18 months. Sputum conversion was observed after one month, cavity closure - by 18 months of treatment. We did not observe cardiotoxic effects due to prolonged bedaquiline use. The administration of prolonged bedaquiline use was based on life-saving considerations. We achieved favourable treatment outcome and demonstrated safety of prolonged bedaquiline use for a child.