Ken Deibert, who has overseen the state's Child Protective Services for nearly two years, is retiring at the end of the month to spend more time with his family in Idaho.
Deibert announced his decision on Tuesday, and a replacement has not been selected.
As the Department of Economic Security's deputy director for the Division of Children, Youth and Families, Deibert oversaw Child Protective Services.
In his time with the agency, Deibert helped create a new tool to assess child safety as well as a statewide program to help keep families together.
He also oversaw the agency during a particularly turbulent period when a number of children with ties to CPS were either killed or allegedly killed at the hands of loved ones.
A message left with Deibert's office was not returned.
But in an e-mail, DES spokeswoman Liz Barker Alvarez said she knew Deibert had "mixed emotions" about retiring.
"Ken cares deeply about children and about the child welfare professionals who work so hard every day to strengthen families," she wrote. "But, he wants to go home to his family in Idaho, and after 35 years in human services, he's ready to explore other interests."
While Deibert was at DES, he also served as President of the National Association of Public Child Welfare Administrators.
Before coming to Arizona, Deibert, a licensed social worker, oversaw child welfare services for the Idaho Department of Health and Welfare.