The present invention relates to iontophoretic transdermal delivery of nicotine salts useful for nicotine replacement therapy for an individual in need thereof. The present invention further relates to the iontophoretic transdermal delivery of nicotine maleate and nicotine citrate. Methods of reducing skin irritation generally caused by transdermal nicotine delivery by iontophoretic transdermal delivery of nicotine salts are also disclosed.