The Association of Public Health Epidemiologists in Ontario is an organization of approximately 90 full members who practice epidemiology in Ontario's public health units, as well as more than 150 affiliate members. APHEO's first meeting was in 1991. In 1997, the association was expanded to include affiliate members - those who have an interest in epidemiology and who may work for other health agencies. The group meets quarterly to discuss matters related to public health epidemiology.

To advance and promote the discipline and professional practice of epidemiology in Ontario public health units.

 The excellent leadership and professional expertise of APHEO advances public health in Ontario.

As a professional organization APHEO believes in:

• improving the health of the population;
• a public health system in which Epidemiologists are integral;
• supporting a participatory network of people with an interest in public health epidemiology;
• high standards for the practice of public health epidemiology;
• demonstrating leadership; and
• innovation.