The 5ft-long (1.5m) reptile has become the talk of Pakefield, near Lowestoft, occasionally coming down for a spot of sunbathing outside the local fish and chip shop.
Owner Mike Hamilton said he had tried to entice it down but his iguana was "living the life of Riley" up the tree.
The "toilet-trained, ever-so friendly" pet would return when ready, he added.
"He's been up there for three months now, he's enjoying himself and he won't come down," Mr Hamilton said.
More on this and other news from lizard-friendly Suffolk
The iguana appears to have made his home at the top of the tree and, despite taking the occasional day trip, has so far evaded capture.
Rani Coleman, who works at the chip shop, said: "A customer came in one day and said there was a lizard on the floor.
"We didn't believe it, but there it was, basking in the sun on the pavement."
She said customers told her they had seen the "huge" iguana in various places and when she arrived at work earlier "everyone was there with their binoculars out".
"I knew straight away that they'd found it," she added.
The iguana is currently sitting on its tree-top perch at the end of All Saints Road, about four houses away from where it used to live with its owner.
Source: Reptileexpert.co.uk
Local resident Angela Hills said people were throwing fruit to try to tempt the iguana down from the tree, but she had concerns for the animal's safety as it was close to a busy road.
Mr Hamilton said he did not think his "bull-headed" but harmless iguana wanted to be caught.
A pet iguana has been living up a 30ft (9m) tree for three months after making an escape from its enclosure.