The cases were reported to the department last week. Both people had traveled to a Zika-affected country, the department said.
The mosquito-borne virus has been known for decades, but recently has caused widespread fear in South American countries like Brazil over concerns that it could cause birth defects.
But researchers say Colorado's dry climate makes a Zika outbreak a long shot here.
"I don't think it's likely at all," Brian Foy, a biology professor at Colorado State University, told Colorado Matters in February. "We don't have those species of mosquitoes [the Aedes] in Colorado."
Still, it's possible that travelers to affected countries could bring the virus back to the state. The public health department says more Zika cases are expected in the coming year.
The Centers for Disease Control says common symptoms include fever, muscle pain and headache.
