Here we present a case series from a primate research facility. The index case, a 4-year-old pig-tailed macaque (Macaca nemestrina) experimentally infected with chimeric simian-human immunodeficiency virus (SHIVSF162 P4), developed weight loss and was euthanized. Based on necropsy results the animal was diagnosed with opportunistic atypical mycobacteriosis associated with simian AIDS (SAIDS). Subsequently, tissues from the index animal, as well as tissues and oral mucosal swabs from six SHIV-infected contacts, were analyzed using molecular methods and found to contain nucleic acid sequences characteristic of Mycobacterium tuberculosis complex (MTBC). These data suggest that existing protocols fail to reliably detect MTBC infection in laboratory primates used as experimental models.