While rabies is said to be unknown on the holiday island, there is no certainty about where the monkey originated.
The creature - possibly a gibbon - was being misused illegally by a photo tout in Patong when it bit Madeline Tanner high on the right cheek this afternoon.
Madeline's parents, Jenny and Craig, took their daughter to Patong Hospital for the first of a series of rabies injections.
Tonight the Deputy Superintendent of Patong's Kathu Police Station, Colonel Kittipong Kaikeaw, began a hunt for the monkey.
At the Kathu Police Station, where the family filed a report this evening, Madeline's mother said: ''We were walking through the OTOP bars this afternoon [on Patong's Rat-U-Tit 200 Pi Road] and we saw a monkey in a nappy and a dress.
''My three year old, Gabrielle, was on my back and the man pushed the monkey onto my shoulder. Then the monkey was pushed at Madeline and she got bitten.
''It was only a little nip but it came awfully fast and very close to her eye,'' Jenny Melrose-Tanner said. ''Now my daughter will need five or six followup rabies injections.
''Madeline loves animals and wants to be a vet when she grows up. But she was very distressed.''
Wal Brown, an International Liason Volunteer at Kathu Police Station, said volunteers had noted seven monkeys being offered by touts in Patong's famous walking street, Soi Bangla, on one night recently.
Just last night, national parks officials confiscated five protected slow moving lorises that were also being used illegally as photo props by touts in Soi Bangla.
The father of the girls, Craig Tanner, said the incident was worrying and had taken the fun out of the family's holiday.
The Tanners head back to the Sunshine Coast in Australia in two days after their week-long break on Phuket.
Awat Nitikul, chief of the Environmental Conservation Unit at the Khao Phra Thaew wildlife sanctuary in Thalang, has said people who sight lorises and gibbons in Patong or elsewhere on Phuket should contact him directly on 086-6897040.