Multiphoton microscopy has revealed important insights into cellular behavior in vivo. However, its application in infectious settings often encounters technical, safety and regulatory limitations that prevent its wider use with highly virulent human pathogens. Herein, we present a method that renders multiphoton microscopy in vivo compatible with biosafety level 3 regulations and present an example of its application and potential to visualize a Mycobacterium tuberculosis infection of the mouse lung.