One of the manners of concluding investigation is its dismissal. Investigation duly is dismissed by a special ruling rendered by the competent state prosecutor. Dismissal of investigation is a procedural action that results with the dismissal of criminal proceedings entirely. The state prosecutor dismisses investigations when it comes to conclusion that there is a fulfillment of legal requirements which determine the undertaking of such an action. In any case, the ruling on investigation dismissal expresses unavoidable effects, except in dismissal of procedure, also in interruption of exercising actions which previously for the police have been authorized by state prosecutor as well as interruption of detention on remand and any other measure imposed against the defendant. Within this scientific paper, in order to have a better picture of situation related to dismissal of investigation has been reflected the practical work of the Basic Prosecution of Prishtina, Prizren and Mitrovica for the period of time 2013-2015. In this case, there are conclusions and concrete suggestions considered to be in function of professional advancement of state prosecutor decision-making concerning criminal cases investigation.