Anthony D'Tileo, 23, was arrested and charged with four counts of lewd and lascivious acts against a child under age 14, senior deputy District Attorney Nancy Georgiou said.
He is being held in county jail in Martinez on more than $1 million bail, she said.
Georgiou said D'Tileo was employed at a preschool in Contra Costa County but declined to say whether the victims were students at the school, citing privacy rights.
D'Tileo is scheduled to return to court in Martinez on Thursday to set future court dates.
