This article describes the development since 1883 of training nurses for working with psychiatric patients. Knowledge of this development seems to throw a new light upon the nursing history in the Netherlands. To start with, the vocational training system in psychiatric hospitals developed during exactly the same time as the hospital based educational system for so called 'general nurses'. As a result, both these vocational training routes were acknowledged as 'basic learning routes for nurses' in the Dutch Nursing Law of 1921. The general route gave access to Diploma A, the psychiatric route gave access to Diploma B. This double diploma system placed the Dutch training system for nurses in an isolated position. For most other countries - as well as the International Council of Nurses - considered psychiatry as a field of work in which a nurse could specialise only after having completed a basic training programme as a general nurse. In most countries, the specialization course in psychiatry only took one year. In comparison to those systems, the Dutch programme seemed to offer psychiatric nurses more years of specific training. After World War II, however, also in the Netherlands many people advocated a one diploma system in nursing, with possibilities to specialise. Nevertheless, it took the Dutch until 1997 to introduce this new system, so it seems the old training routes were defended vehemently. Maybe an historic description of the way this psychiatric route had developed, can shed new light upon the aspects of the old educational system that one longed to preserve.