In a 15-minute appearance Friday on the witness stand, the comedian said he hired Pellicano in 1999 but did not know about his tactics.
Pellicano and four other co-defendants have pleaded not guilty to using wiretaps and other tactics to dig up dirt to help clients in legal and other disputes.
Rock says DNA tests later proved he was not the father of the child.
Rock also testified that he hired Pellicano again after the woman claimed the comedian had sexually assaulted her. Rock was never arrested or charged in connection with that allegation.
By Greg Risling