Rights from Article 6 of the Council of Europe�s convention of the protection of Human Rights and Fundamental Freedoms rest on the idea of effective legal protection. The right to a speedy trial is closely related to the concept of a fair trial which cannot be in the case of exaggerated lengthy uncertainty of parties in relation to their rights and obligations to be decided upon before the court. In this context, Croatian administrative dispute the year 2012 was exceptionally significant when a significantly changed system of administrative adjudication in the Republic of Croatia occurred. Besides this new organisation of administrative adjudication and administrative court and High Administrative Court powers emerging from administrative court reforms in the Republic of Croatia which... also reflected on the duration of administrative disputes in the Republic of Croatia, the new Administrative Dispute Act in administrative dispute built in mechanisms the purpose of which is to achieve maximum efficiency of administrative courts. The Croatian legislator expressed the importance of demands for speedy and effective administrative dispute, as well as speedy trial, in the incorporation of the principle of effectiveness in the new Administrative Dispute Act as one of the fundamental principles of administrative court procedure. Normative solutions of the Administrative Dispute Act imply the conclusion that this law is the first step towards efficient administrative dispute or achieving rights to speedy trial for administrative matters. This creates normative presumptions for respecting convention rights to reaching decisions in administrative matters within a reasonable timeframe. Administrative court practice shows that administrative disputes in principle are carried out according to the principle of efficacy. This is supported by statistical data on the average duration of administrative disputes in the Republic of Croatia, which do not exceed a reasonable timeframe according to European Court of Human Rights� standards. However, taking into account that the need to establish a balance between the demand for efficient court procedure and the demand for the right to fair trial in other aspects could be called into question in the case of exaggerated formalism in the interpretation of the principle of effectiveness. In every concrete case, it is necessary to use the process mechanisms of administrative dispute in a way that both demands are met.