The Merseyside club's record signing has scored 11 goals in 15 league games this season, including six in his last five appearances, to help Everton climb back to within a point of the top six.
Martinez has compared Lukaku's impressive consistency to that of Manchester City star Aguero and has challenged the Belgium international to continue to improve.
"He is as good as it gets in the league. Only Sergio Aguero has had a similar impact in the last three years," Martinez said ahead of Saturday's clash with Norwich City.
"It has been great to see that consistency - 27 goals in a calendar year is impressive, but we want him to carry on wanting more. At 22, that should be the drive and focus."
With Everton unbeaten since back-to-back losses to Manchester United and Arsenal in October, Martinez believes the signs are encouraging for his side going forward.
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"I feel this team is ready to reach real strong heights," he said.
"We've had two defeats in 16, and only one in 11 away from home. But the only focus we have until the end of the season is to get better as a group.
"This season was always about having a group that know each other really well. We want to carry on with that."
Swansea City sacked manager Garry Monk this week following a run of one win in 11 league matches, but Martinez feels his former team captain at the club should be proud of his achievements at the Liberty Stadium.
"What he has achieved there is nothing short of remarkable," he added.
"What he achieved last season will be in history for a long time. I am sure he is going to have a refreshing break period and will be ready to come back.
"Ideally you want to see long-term projects and managers being able to put things into place but it's not a subject of debate. It's what happens now in the game and you have to accept it.
"He was my captain at Swansea. We have a really good professional relationship and I respect him a lot. He should feel very proud of what he has achieved."