Rule of Law Performance Index in Kosovo (RoLPIK) is a monitoring mechanism developed to assess the performance of rule of law institutions, with particular focus on the justice system. This index will serve as a platform of open and accessible data for the broader public, and will present the performance of institutions of justice system in Kosovo in recent years. More concretely, this index contains indicators that provide data on perceptions and experiences of citizens of the Republic of Kosovo in relation to the rule of law institutions, as well as structural data representing reasons that are precondition for an efficient and independent functioning of these institutions. This 4th Edition of RoLPIK, analyzes the forth citizen perception survey conducted during June 2018, and it measures the justice system performance in relation to investigation, trial and resolution of cases during 2013- 2017.