The main goal of this thesis is to find determinants of budget transparency of cities and municipalities in Zadar County. Observed budget transparency index OLBI counts the number of released key budget documents on the local unit’s website. Hypotheses, set in accordance with existing literature, are empirically tested on sample of 34 local units of Zadar County - 6 cities and 28 municipalities. Poisson log-linear model is used within the frame of generalized linear models because the variable of interest is countable. Hypotheses are partially confirmed. Results indicate that percentage of households with Internet access, political competitiveness, departure from budget balance and income per capita indeed have a positive impact on OLBI. Surprising results were obtained for size of the local unit and voter turnout - in Zadar County those variables’ effect is negative. Other variables have not been proved significant in explanation of OLBI level. This thesis is valuable because it is the first in the Republic of Croatia that analyzes specific county, and not local units at the level of the whole country. Also, the topic of budget transparency is not yet sufficiently represented in public so writing about it may encourage: the public to be interested in budget documents, the scientists to study different aspects of this problem and the authorities to be more respectful towards the basic right of every citizen as a taxpayer to get an insight into where his money is spent.