Agents assigned to the U.S. Immigration and Customs Enforcement's HSI Drop House Response Group raided the four-bedroom house on Wednesday. The agents knocked on the front door and were given permission to enter.
The aliens are from Mexico, Guatemala, Honduras and El Salvador. There were five teenage boys and 14 women found among the group.
Agents identified several suspected human smugglers at the scene and are conducting interviews as part of an ongoing investigation into a broader smuggling scheme.
This was the largest drop house discovered in the Phoenix metropolitan area since March 2008 when 124 aliens were apprehended at a drop house in Peoria. It's the second largest drop house discovered since ICE began tracking them in January 2006.