Montenegro currently lead England by two points at the top of Group H after five games, and the two teams met in Podgorica on Tuesday night.
The outcome of that match could play a decisive factor in who qualifies automatically for Brazil, but Hodgson is not writing off the prospects of Ukraine, who have played just four games.
The Euro 2012 co-hosts have four of their six remaining fixtures to come at home and a double-header against San Marino to look forward to, which ensures Hodgson still views Ukraine as a threat.
"I know Ukraine had a bad start but they are a good team," said Hodgson.
"I would certainly put them up there as one of the serious rivals, especially on the basis of what we saw in the Euros and what they did when they came to Wembley.
"I always thought it was going to be a bit of a dog fight between some of these teams. Montenegro have stolen a march but I don't really dismiss the others."
Montenegro preserved their advantage at the top thanks to a 1-0 win in Moldova on Friday night and Hodgson is ready for a 'big game' on Tuesday.
"Whatever the result in Moldova it would have still been a big game for us on Tuesday," said Hodgson.
"Montenegro are one of our serious rivals for the top spot and we must do our best to get a win there."