Three cases are presented, each of which had more than 20 positive cultures of sputum for Mycobacterium intracellulare, infiltrations, and a history of bronchiectasis. Two had complete and the third nearly complete, sputum conversion during a program of bronchial hygiene without chemotherapy. It is probable that these cases were only noninvasive colonizations in previously diseases lungs. Recommendations are given for a therapeutic approach in such cases.