The lawsuit filed in federal court alleges the department harbors an "overt culture of sexual abuse" by guards and has turned a blind eye to it, The Denver Post reported Monday.
The suit against the department, filed by 10 female inmates last month, claims in more than a dozen instances at two prisons -- the Denver Women's Correctional Facility and the since-closed privately run Brush Correctional Facility -- officers forced women to perform sex acts on them.
If the women did not submit, officers would threaten to have them "written up" or to make life hard for them, the lawsuit claims.
"This conduct amounts to deliberate indifference to the rights of inmates," the lawsuit says.
Katherine Sanguinetti, a Corrections Department spokeswoman, said the department would not comment on ongoing litigation.
Department officials have a zero-tolerance policy regarding sexual misconduct by corrections officers, she said.