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     The CMLTO is operating virtually with the office located at 25 Adelaide Street East closed to the public until
     further notice. Click here for more information about contacting the CMLTO by email or postal mail.
    During the COVID-19 pandemic, healthcare organizations have increasingly become targets of cyberattacks.
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    about its legitimacy, please email communications@cmlto.com for clarification.
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The CMLTO Voluntary Roster of Registered Medical Laboratory Technicians
Click here to apply.
Learn more about the Voluntary Roster initiative by clicking here

Click here to search the Voluntary Roster.

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CMLTO closed on October 11, 2021

08 October 2021

The CMLTO will be closed for the statutory Thanksgiving holiday on October 11, 2021. Regular hours resume at 8:30 am on October 12th.

Registration renewal begins November 1, 2021

01 October 2021

The CMLTO's Annual Registration Renewal for 2022 begins on November 1, 2021. All medical laboratory technologists registered in Ontario must renew their CMLTO registration online by December 31, 2021.

The Annual Registration Renewal notice, which includes renewal instructions, will be sent by postal mail in the third week of October. It is a professional obligation to ensure that the CMLTO has your correct contact information. Registrants can update their profiles by logging into

CMLTO Board of Directors announces new Registrar & CEO

30 September 2021

From Tammy Earle, MLT
Chair, CMLTO Board of Directors

On behalf of the CMLTO Board of Directors, I am pleased to announce the appointment of John Tzountzouris as the new CMLTO Registrar & CEO. John’s tenure begins on October 4, 2021.

John has worked at the CMLTO since 2009, beginning as Senior Policy & Knowledge Management Specialist, and most recently as Director, Registration & Professional Practice since 2017.

John received a BSc in Biochemistry from McMaster University in 1996 and a diploma in Medical Laboratory Technology (Molecular Genetics) in 1997 from The Michener Institute for Applied Health Sciences. He went on to receive a Bachelor’s in Health Administration and a Master’s in Public Policy from Ryerson University. John was designated a Governance System Professional by Govern for Impact in 2020.

Since 2019 John has volunteered on the Board of Girls Inc. Durham that began as a branch of the Big Sisters movement and advocates on behalf of girls and delivers life-changing programs and experiences. He currently serves as Board President.

The CMLTO Board looks forward to working with John to continue protecting Ontarians through self-regulation of the medical laboratory technology profession.

image of medical laboratory technologist at microscope