The article attempts to contribute to the whole momentum of finding the cause of type 1 diabetes (T1D), exhibiting the global growth in the incidence of 3% per year, but more intense in developing economies of Europe. As there is still no conclusion about the real cause of T1D, although a number of environmental factors in a focus, a hypothesis was raised that the possible main trigger is still not identified. The main method applied was screening of the scientific publications presenting geographical, epidemiological and etiological studies of T1D. The geographical, migrant, etiological and other facts suggesting a direct implication (deduced assumption) about the features of the top trigger of T1D were collected, discussed and used for deduction of assumptions, organized in a hierarchical order. The final assumption was drawn indicating the discussable candidate for the top trigger of T1D as a synthetic medicine administrated in times of viral infections with increasing popularity among the youngest population.