Infection as an environmental factor in autoimmunity has long been recognized. Numerous examples can be found in which pathogens express antigens that cross-react with host antigens or induce local inflammatory responses that can lead to autoimmune responses through a very complex set of circumstances. Borrowing from the relationship between chronic infection with hepatitis C virus and autoimmune hepatitis as an example, we consider the possibility that infection with an unknown virus having specific tissue tropism could lead to a perceived autoimmune process. We raise the question whether such should be considered for Type 1 diabetes.