PURPOSE OF REVIEW: Pulmonary nontuberculous mycobacterial disease (NTM) remains a significant clinical challenge with suboptimal therapy. This review focuses on recent understandings around the pathogenesis of NTM disease and nonantibiotic therapeutic approaches that are being pursued. RECENT FINDINGS: The absence of animal models that truly replicate human disease remains a major problem for NTM research with most findings coming from tuberculosis or tuberculosis-like studies. Recent research reiterates the known key roles of interferon gamma (IFNγ), tumor necrosis factor, interleukin-12 and granulocyte-macrophage colony stimulation factor (GM-CSF) in immunity to NTM. Autoantibodies to some of these factors may be important. Recent nonantibiotic research has focused on either boosting the immune response to NTM (e.g. with IFNγ or GM-CSF) or using other compounds to kill these pathogens (e.g. inhaled NO, gallium, etc.). SUMMARY: Our poor understanding of the immune deficit leading to NTM disease continues to hinder the development of highly effective therapies. New approaches are promising but need significant validation before being considered viable therapeutic options.