Hagan filed a lawsuit in Wake County Superior Court after Dole declined to remove the ad from the air by a noon deadline.
"Each airing of the advertisement further injures (Hagan's) good name and reputation in the community," Hagan's attorneys wrote in the complaint.
Dole campaign spokesman Dan McLagan dismissed the lawsuit as a "silly political gimmick."
Dole's campaign had called Hagan's earlier warning of a lawsuit an empty threat, and her attorneys said in a letter the ad simply states facts.
"Your client may not like that the ad publicly disseminates information she would prefer to keep quiet in these days before the elections, but the ad is 100% factually accurate and truthful," the attorneys wrote.
Released this week, Dole's ad questions why Hagan went to a fundraiser at the home of a man who serves as an adviser to the Godless Americans Political Action Committee. The ad ends by showing a picture of Hagan while another woman declares in the background, "There is no God!"
Hagan is a Presbyterian church elder who teaches Sunday school. She responded with an ad Thursday in which she forcefully declares her belief in God and cites the Bible's 9th Commandment in decrying Dole for "bearing false witness against fellow Christians."
Thursday's court filing does not detail Hagan's full case against Dole, but initiates the case and allows Hagan 20 days to file the full complaint.