This thesis analyses short – term heavy precipitation in the areas of Istria and Zagreb. The precipitation data obtained by measurements at eight stations in Istria and five in Zagreb are analysed. At the beginning something general is said about precipitation and its occurrence in Croatia. The climatic characteristics of the area of Istria, which represents the rural environment, and the area of Zagreb, which represents the urban environment, are shown in this thesis. Also, a brief overview of the data is given and the available substrates are shown. Something has been said about the data processing methodology which includes primary processing and control, standard statistical indicators, probabilities of maximum precipitation and defining HTP curves. A brief overview of the treatment of short – term heavy precipitation at the regional level and worldwide is given. Annual HTP curves of certain return periods are based on the calculated amounts of precipitation and annual HTP curves of certain return periods have been made. The interrelationship of annual HTP curves in modular values are also analysed. Furthermore a comparison of maximum precipitation for individual durations in the wider area of Zagreb and Istria has been made and appropriate envelopes have been determined. Finally, an analysis of the monthly and seasonal HTP curves for the four selected stations is presented. Due to inadequate drainage solutions and the possible impacts of climate change short – term heavy precipitation can lead to major problems and harmful consequences in urban areas. To conclude, it is of particular importance to analyze and estimate the amount of precipitation for different return periods.