Heartthrob? Star athlete? Sexiest Man Alive? All of these have been used in conjunction with Mark Harmon, star of the hit drama NCIS. With acting credits including Chicago Hope, The West Thing and St.Elsewhere, Mark Harmon is one performer who needs little introduction. it's safe to say his fans span the entire globe. So how big of a fan are you?

Take the quiz to see how much you know about NCIS star Mark Harmon.