A man and his dog have been shot on a highway in Sydney's south.


Police were called to the Princes Highway at Tempe on Saturday afternoon and found the man, who is in his 30s, with a bullet wound to his leg.


The man's dog had also been shot, a police spokeswoman told AAP.


The condition of both was unavailable, she added.


She was unable to say whether the man was known to police.


Two of the three northbound lanes on the Princes Highway were closed following the shooting, the Transport Management Centre (TMC) said.


Traffic is queued about a kilometre and the TMC said drivers "should allow plenty of extra travel time."


All southbound lanes were open


AAP