Geralt's mother is Visenna, a Sorceress, Healer and Druid, Protagonist of the story "Road with no return"as for Father. Initialy, Sapkowski didn't intend on revealing the identity of Geralt's father, But it was later stated (by the creators of the comic book) that Geralt's father was Korim, second protagonist of the "road..."It seems partialy confirmed, when Geralt states in "Time of Disdain" that his father was a mercenary and fighter, the tescription fitng Korin quite well