The Dutch Association of Psychologists (NIP) finds it is very important that the work of psychologists is of good quality. That is why the NIP has drawn up a Code of Ethics for Psychologists and also the new Guidelines for the Use of Tests AST-NIP 2017. The Code of Ethics contains guidelines and rules of conduct that apply to the professional conduct of a psychologist. The basic principles are that the psychologist must behave responsible, integer, respectful and with expertise. The AST-NIP 2017 is an elaboration and specification of the Code of Ethics and contains guidelines and information for making a responsible choice of instruments and the proper use of psychodiagnostic instruments in the context of psychodiagnostics and /or psychological interventions.