In May 2019, controversy arose when a prominent Australian
urologist, Professor Henry Woo, commented on the large number of
GoFundMe campaigns requesting considerable sums of money for patients to have surgery done by Teo when Australia's public health system should be performing any required surgery in the public system. Professor Woo also questioned the absence of peer-reviewed evidence that Teo's operative approach was beneficial to patients with incurable brain cancer. In 2021, the NSW Medical Council conducted a special hearing into Teo's behaviours during surgical procedures; and, following investigation, he was prevented from performing any "recurrent malignant intracranial tumour and brain stem tumour surgical procedures" unless he obtained written approval from an independent neurosurgeon, as approved by the NSW Medical Council. Teo was also investigated by the
Health Care Complaints Commission. In 2022, it was reported that Teo is performing surgeries in Spain, which is beyond the regulatory powers of the NSW Medical Council. On 23 October 2022, the
Sydney Morning Herald described how Teo charged families extraordinary amounts of money and gave hope for a cure for ultimately futile operations that have catastrophically injured his patients. The article discussed two cases of operations on children with
Diffuse Intrinsic Pontine Glioma (DIPG), an inoperable tumour, which, despite Teo's reassurance to their families that these surgeries could cure DIPG, did not provide a cure. In an interview on
A Current Affair, Teo sought to justify his interventions. In a podcast with
Mark Bouris, Teo would claim that the accusations being levelled against him are from business rivals and personal enemies. During the hearing, it was reported that Teo slapped a patient who was unconscious in front of the patient's family, while Teo downplayed the intensity of the slap, calling it a light tap through a pantomime. Teo's conduct has been criticised by other Australian neurosurgeons. Amidst the controversy, a number of neurosurgeons globally, as well as other medical colleagues, supported Teo. In letters of support to the Health Care Complaints Commission, Professor Yeo Tseng Tsai, head of neurosurgery at
National University Hospital Singapore lauded Teo as 'a world class neurosurgeon of the first order'. Professor Paul Gardiner, neurosurgery director at
University of Pittsburgh Medical Center described Teo as 'among a small set of gifted and dedicated surgeons who can offer the most complicated patients a chance where other (neurosurgeons) cannot'. Dr Robert L. Dodd of
Stanford School of Medicine affirmed that Teo's 'skill as a surgeon is superb and his surgical outcomes were extraodinary'. Director of Brain Tumor and Skull Base Surgery at Providence Brain and Spine Institute Dr Gore writes in 'unequivocal support of Dr Charlie Teo ... his heightened skills in handling critical neural and vascular structures and differentiating tumor from non-neoplastic tissue put him in a position to perform surgery that many other neurosurgeons are not capable of'. Professor of Neurosurgery Nikolai J Hopf of
University of Mainz, Germany, described Teo as 'one of the most important opinion leaders in the field of glioma surgery... his impact on modern surgical treatment of patients with gliomas and in particular complex gliomas is outstanding...', noting that if Teo's 'registration was suspended, cancelled, or otherwise restricted, patients as well as the Neurosurgical community would lose one of the most skillful glioma surgeons'. In August 2023, Teo and a former patient reached an
out-of-court settlement just prior to a seven-day medical negligence hearing. Teo had operated twice on the patient, who had a
grade 3 anaplastic astrocytoma. The patient subsequently lost movement down one side of his body, as well as having visual and cognitive impairment. He has limited life expectancy, possibly less than a year. Teo denied he had been negligent. In approving judgment for the patient, Supreme Court Justice Richard Cavanagh said "the settlement reflects the top of the range for the plaintiff". In March 2025, Teo agreed to pay an undisclosed settlement amount to the family of a patient who died soon after he operated on her incurable brain tumour. He had previously been found guilty of professional misconduct over the operation in question. Responding to public criticism of his billing practices, Teo claimed in 2025 that he did not charge "more than half" of his patients during his career, including medical staff, police officers, and pensioners. Following the restrictions placed on his surgical practice in Australia, Teo now travels internationally to countries like Spain to mentor other surgeons, guiding them through operations as a non-participating observer. == Personal life ==