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.

In Dublin, a military ceremonial event was held at the War Memorial Gardens at Islandbridge.
A military service was also held at the Mall in Cork.
Irish President Michael D Higgins travelled to Thiepval in France to pay tribute to the Irishmen who died while serving in the British, Commonwealth or US armies.
He was accompanied by the the Irish minister for arts, heritage and the Gaeltacht, Heather Humphreys.
The village of Thiepval in France is close to where the 36th Ulster Division began their attack on German lines on 1 July 1916 and is now the site of the Ulster Memorial Tower, a 70ft (21m) monument which commemorates their sacrifice.
Men from all over the island of Ireland fought at the Somme, and the service in France will also be attended by representatives from the British and French governments also.
Many people from the Republic of Ireland and Northern Ireland, including relatives of Somme veterans, have travelled to Thiepval for the commemoration event.
The ceremony in Dublin began at 07:28 local time - the time the battle started 100 years ago.
It was attended by members of the Irish Defence Forces and the Royal British Legion.

During a "very busy two hour period" on Friday, the fire service said it received more than 100 calls to over 30 flooding incidents in Southend.
Six people were rescued after their vehicles got stuck at a flooded roundabout on Woodgrange Drive.
The roof of the Pearl Dragon restaurant collapsed under the weight of the rain. No-one was hurt.
Crews were also sent to the Sea Life Centre, opposite the restaurant on the Eastern Esplanade, to pump water from the building.
Martin Richardson, owner of the Happidrome on Southend's Golden Mile, said the amusement arcade had been overcome by water.
"It came through the back, the side, it came through the wall, it came through the roof, the main drains," he said. "At least four of the arcades on the promenade suffered.
"It's going to be a long while before we're open."
Mark Baumann, owner of the Bourgee restaurant on the seafront, said he watched in vain as flood water entered the building.
"I've never seen rain like it," he said. "The water started to come into the restaurant, and then it went further, and further.
"It was all hands on deck - some of the customers helped to squeegee the water away."
The rain has resulted in traffic delays, with the A12 London-bound at Witham blocked by flood water.
BBC Travel has the latest on the disruption.
A pet iguana has been living up a 30ft (9m) tree for three months after making an escape from its enclosure.
[NEXT_CONCEPT]
The centenary of the Battle of the Somme has been marked with ceremonies in the Republic of Ireland.
[NEXT_CONCEPT]
Six people were rescued from cars trapped in flood water, as heavy rain hit Essex overnight.