This editorial provides an overview of how far access to mental health care is limited by perceptions of stigma and anticipated discrimination. Globally over 70% of young people and adults with mental illness receive no treatment from healthcare staff. The rates of non-treatment are far higher in low income countries. Evidence from some descriptive studies and epidemiological surveys suggest that potent factors increasing the likelihood of treatment avoidance, or long delays before presenting for care include: (i) lack of knowledge about the features and treatability of mental illnesses; (ii) ignorance about how to access assessment and treatment; (iii) prejudice against people who have mental illness, and (iv) expectations of discrimination against people who have a diagnosis of mental illness. The associations between low rates of help seeking, and stigma and discrimination are as yet poorly understood and require more careful characterisation and analysis, providing the platform for more effective action to ensure that a greater proportion of people with mental illness are effectively treated in future.