Composition of spider communities is a good indicator of the condition and stability of habitat, and can serve as bioindicator of diversity and conservation status of terrestrial habitats. Determination of environmental determinants influencing spider distribution and application of predictive distribution modelling may focus research on priority conservation areas, reduce financial costs and accelerate the implementation of conservation measures. By processing data from museum collections, literature and recent research, a complete list of Croatian spider fauna and digital database was created allowing spatial analysis of the state of spider research. In total, 821 species is listed, belonging to 305 genera from 45 families. Thirty species are considered endemic to Croatia, with additional 31 Balkan Peninsula endemics. Eighty-one percent of Croatian spider fauna has Palearctic distribution, followed by Holarctic species (10%) and species distributed on Saharo-Arabian and Palearctic realm. Taking into account low research completeness and country size, Croatia is above European average on the number of recorded species. Through comparison of faunistic data and different environmental variables, it was confirmed that temperature, humidity and vegetation structure are the main environmental determinants of diversity and composition of spider fauna. Using these environmental variables predictive distribution models for species Nesticus eremita and Latrodectus tredecimguttatus were developed.