The Belgian international, 22, is currently enjoying a season-long loan with Everton.
While Lukaku has been linked with a permanent switch to the Toffees, Pardew believes that the Merseysiders will face stern competition for the youngster's signature.
"I think he is a player a lot of clubs will be looking at in the summer. I don't think Everton will get a free run at him," he is quoted as saying by Sky Sports News.
"At the moment, it is a bit like we are with Loic (Remy). It is a situation that Everton would love to keep him, as we would with Loic, and those questions are really out of Everton's and our control."
Lukaku has scored 12 goals in 24 games for Everton during the current campaign.